{"id":457,"date":"2021-02-04T15:27:58","date_gmt":"2021-02-04T15:27:58","guid":{"rendered":"https:\/\/courses.lumenlearning.com\/calculus1\/?post_type=chapter&#038;p=457"},"modified":"2021-06-22T05:39:39","modified_gmt":"2021-06-22T05:39:39","slug":"problem-set-the-limit-laws","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/calculus1\/chapter\/problem-set-the-limit-laws\/","title":{"raw":"Problem Set: The Limit Laws","rendered":"Problem Set: The Limit Laws"},"content":{"raw":"<p id=\"fs-id1170572597920\">In the following exercises (1-4), use the limit laws to evaluate each limit. Justify each step by indicating the appropriate limit law(s).<\/p>\r\n\r\n<div id=\"fs-id1170572597924\" class=\"exercise\">\r\n<div id=\"fs-id1170572597926\" class=\"textbox\">\r\n<p id=\"fs-id1170572597929\"><strong>1.\u00a0<\/strong>[latex]\\underset{x\\to 0}{\\lim}(4x^2-2x+3)[\/latex]<\/p>\r\n[reveal-answer q=\"fs-id1170572597974\"]Show Solution[\/reveal-answer]\r\n[hidden-answer a=\"fs-id1170572597974\"]\r\n<p id=\"fs-id1170572597974\">Use constant multiple law and difference law: [latex]\\underset{x\\to 0}{\\lim}(4x^2-2x+3)=4\\underset{x\\to 0}{\\lim}x^2-2\\underset{x\\to 0}{\\lim}x+\\underset{x\\to 0}{\\lim}3=3[\/latex]<\/p>\r\n[\/hidden-answer]\r\n\r\n<\/div>\r\n<\/div>\r\n<div id=\"fs-id1170572347613\" class=\"exercise\">\r\n<div id=\"fs-id1170572347616\" class=\"textbox\">\r\n<p id=\"fs-id1170572347618\"><strong>2.\u00a0<\/strong>[latex]\\underset{x\\to 1}{\\lim}\\frac{x^3+3x^2+5}{4-7x}[\/latex]<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<div id=\"fs-id1170571574688\" class=\"exercise\">\r\n<div id=\"fs-id1170571574690\" class=\"textbox\">\r\n<p id=\"fs-id1170571574692\"><strong>3.\u00a0<\/strong>[latex]\\underset{x\\to -2}{\\lim}\\sqrt{x^2-6x+3}[\/latex]<\/p>\r\n[reveal-answer q=\"fs-id1170571574734\"]Show Solution[\/reveal-answer]\r\n[hidden-answer a=\"fs-id1170571574734\"]\r\n<p id=\"fs-id1170571574734\">Use root law: [latex]\\underset{x\\to -2}{\\lim}\\sqrt{x^2-6x+3}=\\sqrt{\\underset{x\\to -2}{\\lim}(x^2-6x+3)}=\\sqrt{19}[\/latex]<\/p>\r\n[\/hidden-answer]\r\n\r\n<\/div>\r\n<\/div>\r\n<div id=\"fs-id1170572229064\" class=\"exercise\">\r\n<div id=\"fs-id1170572229066\" class=\"textbox\">\r\n\r\n<strong>4.\u00a0<\/strong>[latex]\\underset{x\\to -1}{\\lim}(9x+1)^2[\/latex]\r\n\r\n<\/div>\r\n<\/div>\r\n<p id=\"fs-id1170572229201\">In the following exercises (5-10), use direct substitution to evaluate each limit.<\/p>\r\n\r\n<div id=\"fs-id1170572229204\" class=\"exercise\">\r\n<div id=\"fs-id1170572229206\" class=\"textbox\">\r\n<p id=\"fs-id1170572229209\"><strong>5.\u00a0<\/strong>[latex]\\underset{x\\to 7}{\\lim}x^2[\/latex]<\/p>\r\n[reveal-answer q=\"fs-id1170571654822\"]Show Solution[\/reveal-answer]\r\n[hidden-answer a=\"fs-id1170571654822\"]\r\n<p id=\"fs-id1170571654822\">49<\/p>\r\n[\/hidden-answer]\r\n\r\n<\/div>\r\n<\/div>\r\n<div id=\"fs-id1170571654827\" class=\"exercise\">\r\n<div id=\"fs-id1170571654830\" class=\"textbox\">\r\n<p id=\"fs-id1170571654832\"><strong>6.\u00a0<\/strong>[latex]\\underset{x\\to -2}{\\lim}(4x^2-1)[\/latex]<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<div id=\"fs-id1170571654878\" class=\"exercise\">\r\n<div id=\"fs-id1170571654880\" class=\"textbox\">\r\n<p id=\"fs-id1170571654882\"><strong>7.\u00a0<\/strong>[latex]\\underset{x\\to 0}{\\lim}\\dfrac{1}{1+ \\sin x}[\/latex]<\/p>\r\n[reveal-answer q=\"fs-id1170571654916\"]Show Solution[\/reveal-answer]\r\n[hidden-answer a=\"fs-id1170571654916\"]\r\n<p id=\"fs-id1170571654916\">1<\/p>\r\n[\/hidden-answer]\r\n\r\n<\/div>\r\n<\/div>\r\n<div id=\"fs-id1170571654921\" class=\"exercise\">\r\n<div id=\"fs-id1170571654923\" class=\"textbox\">\r\n<p id=\"fs-id1170571654925\"><strong>8.\u00a0<\/strong>[latex]\\underset{x\\to 2}{\\lim}e^{2x-x^2}[\/latex]<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<div id=\"fs-id1170571654968\" class=\"exercise\">\r\n<div id=\"fs-id1170571654970\" class=\"textbox\">\r\n<p id=\"fs-id1170571654972\"><strong>9.\u00a0<\/strong>[latex]\\underset{x\\to 1}{\\lim}\\dfrac{2-7x}{x+6}[\/latex]<\/p>\r\n[reveal-answer q=\"fs-id1170572482577\"]Show Solution[\/reveal-answer]\r\n[hidden-answer a=\"fs-id1170572482577\"]\r\n<p id=\"fs-id1170572482577\">[latex]-\\frac{5}{7}[\/latex]<\/p>\r\n[\/hidden-answer]\r\n\r\n<\/div>\r\n<\/div>\r\n<div id=\"fs-id1170572482590\" class=\"exercise\">\r\n<div id=\"fs-id1170572482593\" class=\"textbox\">\r\n<p id=\"fs-id1170572482595\"><strong>10.\u00a0<\/strong>[latex]\\underset{x\\to 3}{\\lim}\\ln e^{3x}[\/latex]<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<p id=\"fs-id1170572482632\">In the following exercises (11-20), use direct substitution to show that each limit leads to the indeterminate form [latex]\\frac{0}{0}[\/latex]. Then, evaluate the limit.<\/p>\r\n\r\n<div id=\"fs-id1170572482649\" class=\"exercise\">\r\n<div id=\"fs-id1170572482652\" class=\"textbox\">\r\n<p id=\"fs-id1170572482654\"><strong>11.\u00a0<\/strong>[latex]\\underset{x\\to 4}{\\lim}\\dfrac{x^2-16}{x-4}[\/latex]<\/p>\r\n[reveal-answer q=\"fs-id1170572482694\"]Show Solution[\/reveal-answer]\r\n[hidden-answer a=\"fs-id1170572482694\"]\r\n<p id=\"fs-id1170572482694\">[latex]\\underset{x\\to 4}{\\lim}\\frac{x^2-16}{x-4}=\\frac{16-16}{4-4}=\\frac{0}{0}[\/latex]; then, [latex]\\underset{x\\to 4}{\\lim}\\frac{x^2-16}{x-4}=\\underset{x\\to 4}{\\lim}\\frac{(x+4)(x-4)}{x-4}=8[\/latex]<\/p>\r\n[\/hidden-answer]\r\n\r\n<\/div>\r\n<\/div>\r\n<div id=\"fs-id1170572403294\" class=\"exercise\">\r\n<div id=\"fs-id1170572403296\" class=\"textbox\">\r\n<p id=\"fs-id1170572403299\"><strong>12.\u00a0<\/strong>[latex]\\underset{x\\to 2}{\\lim}\\dfrac{x-2}{x^2-2x}[\/latex]<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<div id=\"fs-id1170571586166\" class=\"exercise\">\r\n<div id=\"fs-id1170571586168\" class=\"textbox\">\r\n<p id=\"fs-id1170571586170\"><strong>13.\u00a0<\/strong>[latex]\\underset{x\\to 6}{\\lim}\\dfrac{3x-18}{2x-12}[\/latex]<\/p>\r\n[reveal-answer q=\"fs-id1170571586209\"]Show Solution[\/reveal-answer]\r\n[hidden-answer a=\"fs-id1170571586209\"][latex]\\underset{x\\to 6}{\\lim}\\frac{3x-18}{2x-12}=\\frac{18-18}{12-12}=\\frac{0}{0}[\/latex]; then, [latex]\\underset{x\\to 6}{\\lim}\\frac{3x-18}{2x-12}=\\underset{x\\to 6}{\\lim}\\frac{3(x-6)}{2(x-6)}=\\frac{3}{2}[\/latex]\r\n[\/hidden-answer]\r\n\r\n<\/div>\r\n<\/div>\r\n<div id=\"fs-id1170572503561\" class=\"exercise\">\r\n<div id=\"fs-id1170572503563\" class=\"textbox\">\r\n<p id=\"fs-id1170572503565\"><strong>14.\u00a0<\/strong>[latex]\\underset{h\\to 0}{\\lim}\\dfrac{(1+h)^2-1}{h}[\/latex]<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<div id=\"fs-id1170572499899\" class=\"exercise\">\r\n<div id=\"fs-id1170572499901\" class=\"textbox\">\r\n<p id=\"fs-id1170572499903\"><strong>15.\u00a0<\/strong>[latex]\\underset{t\\to 9}{\\lim}\\dfrac{t-9}{\\sqrt{t}-3}[\/latex]<\/p>\r\n[reveal-answer q=\"fs-id1170572499942\"]Show Solution[\/reveal-answer]\r\n[hidden-answer a=\"fs-id1170572499942\"]\r\n<p id=\"fs-id1170572499942\">[latex]\\underset{t \\to 9}{\\lim}\\frac{t-9}{\\sqrt{t}-3}=\\frac{9-9}{3-3}=\\frac{0}{0}[\/latex]; then, [latex]\\underset{t\\to 9}{\\lim}\\frac{t-9}{\\sqrt{t}-3}=\\underset{t\\to 9}{\\lim}\\frac{t-9}{\\sqrt{t}-3}\\frac{\\sqrt{t}+3}{\\sqrt{t}+3}=\\underset{t\\to 9}{\\lim}(\\sqrt{t}+3)=6[\/latex]<\/p>\r\n[\/hidden-answer]\r\n\r\n<\/div>\r\n<\/div>\r\n<div id=\"fs-id1170571655854\" class=\"exercise\">\r\n<div id=\"fs-id1170571655856\" class=\"textbox\">\r\n<p id=\"fs-id1170571655859\"><strong>16.\u00a0<\/strong>[latex]\\underset{h\\to 0}{\\lim}\\dfrac{\\frac{1}{a+h}-\\frac{1}{a}}{h}[\/latex], where [latex]a[\/latex] is a real-valued constant<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<div id=\"fs-id1170571657390\" class=\"exercise\">\r\n<div id=\"fs-id1170571657392\" class=\"textbox\">\r\n<p id=\"fs-id1170571657395\"><strong>17.\u00a0<\/strong>[latex]\\underset{\\theta \\to \\pi}{\\lim}\\dfrac{\\sin \\theta}{\\tan \\theta}[\/latex]<\/p>\r\n\r\n<div id=\"fs-id1170571657390\" class=\"exercise\">\r\n\r\n[reveal-answer q=\"fs-id1170571657432\"]Show Solution[\/reveal-answer]\r\n[hidden-answer a=\"fs-id1170571657432\"][latex]\\underset{\\theta \\to \\pi}{\\lim}\\frac{\\sin \\theta}{\\tan \\theta}=\\frac{\\sin \\pi}{\\tan \\pi}=\\frac{0}{0}[\/latex]; then, [latex]\\underset{\\theta \\to \\pi}{\\lim}\\frac{\\sin \\theta}{\\tan \\theta}=\\underset{\\theta \\to \\pi}{\\lim}\\frac{\\sin \\theta}{\\frac{\\sin \\theta}{\\cos \\theta}}=\\underset{\\theta \\to \\pi}{\\lim}\\cos \\theta =-1[\/latex].\r\n[\/hidden-answer]\r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n<div id=\"fs-id1170571599916\" class=\"exercise\">\r\n<div id=\"fs-id1170571599918\" class=\"textbox\">\r\n<p id=\"fs-id1170571599920\"><strong>18.\u00a0<\/strong>[latex]\\underset{x\\to 1}{\\lim}\\dfrac{x^3-1}{x^2-1}[\/latex]<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<div id=\"fs-id1170572551466\" class=\"exercise\">\r\n<div id=\"fs-id1170572551468\" class=\"textbox\">\r\n<p id=\"fs-id1170572551470\"><strong>19.\u00a0<\/strong>[latex]\\underset{x\\to 1\/2}{\\lim}\\dfrac{2x^2+3x-2}{2x-1}[\/latex]<\/p>\r\n[reveal-answer q=\"fs-id1170572551526\"]Show Solution[\/reveal-answer]\r\n[hidden-answer a=\"fs-id1170572551526\"]\r\n<p id=\"fs-id1170572551526\">[latex]\\underset{x\\to 1\/2}{\\lim}\\frac{2x^2+3x-2}{2x-1}=\\frac{\\frac{1}{2}+\\frac{3}{2}-2}{1-1}=\\frac{0}{0}[\/latex]; then, [latex]\\underset{x\\to 1\/2}{\\lim}\\frac{2x^2+3x-2}{2x-1}=\\underset{x\\to 1\/2}{\\lim}\\frac{(2x-1)(x+2)}{2x-1}=\\frac{5}{2}[\/latex]<\/p>\r\n[\/hidden-answer]\r\n\r\n<\/div>\r\n<\/div>\r\n<div id=\"fs-id1170571599675\" class=\"exercise\">\r\n<div id=\"fs-id1170571599677\" class=\"textbox\">\r\n<p id=\"fs-id1170571599679\"><strong>20.\u00a0<\/strong>[latex]\\underset{x\\to -3}{\\lim}\\dfrac{\\sqrt{x+4}-1}{x+3}[\/latex]<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<p id=\"fs-id1170572174650\">In the following exercises (21-24), use direct substitution to obtain an undefined expression. Then, use the method of <a class=\"autogenerated-content\" href=\"#fs-id1170571611196\">(Figure)<\/a> to simplify the function to help determine the limit.<\/p>\r\n\r\n<div id=\"fs-id1170572174658\" class=\"exercise\">\r\n<div id=\"fs-id1170572174658\" class=\"exercise\">\r\n<div id=\"fs-id1170572174660\" class=\"textbox\">\r\n<p id=\"fs-id1170572174662\"><strong>21.\u00a0<\/strong>[latex]\\underset{x\\to -2^-}{\\lim}\\dfrac{2x^2+7x-4}{x^2+x-2}[\/latex]<\/p>\r\n[reveal-answer q=\"fs-id1170572174724\"]Show Solution[\/reveal-answer]\r\n[hidden-answer a=\"fs-id1170572174724\"]\r\n<p id=\"fs-id1170572174724\">[latex]-\\infty[\/latex]<\/p>\r\n[\/hidden-answer]\r\n\r\n<\/div>\r\n<\/div>\r\n<div id=\"fs-id1170572174729\" class=\"exercise\">\r\n<div id=\"fs-id1170572174731\" class=\"textbox\">\r\n<p id=\"fs-id1170572174734\"><strong>22.\u00a0<\/strong>[latex]\\underset{x\\to -2^+}{\\lim}\\dfrac{2x^2+7x-4}{x^2+x-2}[\/latex]<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<div id=\"fs-id1170572174801\" class=\"exercise\">\r\n<div id=\"fs-id1170572174803\" class=\"textbox\">\r\n<p id=\"fs-id1170572174805\"><strong>23.\u00a0<\/strong>[latex]\\underset{x\\to 1^-}{\\lim}\\dfrac{2x^2+7x-4}{x^2+x-2}[\/latex]<\/p>\r\n[reveal-answer q=\"fs-id1170571610806\"]Show Solution[\/reveal-answer]\r\n[hidden-answer a=\"fs-id1170571610806\"]\r\n<p id=\"fs-id1170571610806\">[latex]-\\infty[\/latex]<\/p>\r\n[\/hidden-answer]\r\n\r\n<\/div>\r\n<div class=\"textbox\"><strong>24. <\/strong>[latex]\\underset{x\\to 1^+}{\\lim}\\dfrac{2x^2+7x-4}{x^2+x-2}[\/latex]<\/div>\r\n<\/div>\r\n<\/div>\r\n<p id=\"fs-id1170571610881\">In the following exercises (25-32), assume that [latex]\\underset{x\\to 6}{\\lim}f(x)=4, \\, \\underset{x\\to 6}{\\lim}g(x)=9[\/latex], and [latex]\\underset{x\\to 6}{\\lim}h(x)=6[\/latex]. Use these three facts and the limit laws to evaluate each limit.<\/p>\r\n\r\n<div id=\"fs-id1170571610978\" class=\"exercise\">\r\n<div id=\"fs-id1170571610980\" class=\"textbox\">\r\n<p id=\"fs-id1170571610983\"><strong>25.\u00a0<\/strong>[latex]\\underset{x\\to 6}{\\lim}2f(x)g(x)[\/latex]<\/p>\r\n[reveal-answer q=\"fs-id1170571669784\"]Show Solution[\/reveal-answer]\r\n[hidden-answer a=\"fs-id1170571669784\"]\r\n<p id=\"fs-id1170571669784\">[latex]\\underset{x\\to 6}{\\lim}2f(x)g(x)=2\\underset{x\\to 6}{\\lim}f(x)\\underset{x\\to 6}{\\lim}g(x)=72[\/latex]<\/p>\r\n[\/hidden-answer]\r\n\r\n<\/div>\r\n<\/div>\r\n<div id=\"fs-id1170571669881\" class=\"exercise\">\r\n<div id=\"fs-id1170571669883\" class=\"textbox\">\r\n<p id=\"fs-id1170571669885\"><strong>26.\u00a0<\/strong>[latex]\\underset{x\\to 6}{\\lim}\\dfrac{g(x)-1}{f(x)}[\/latex]<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<div id=\"fs-id1170572480473\" class=\"exercise\">\r\n<div id=\"fs-id1170572480476\" class=\"textbox\">\r\n<p id=\"fs-id1170572480478\"><strong>27.\u00a0<\/strong>[latex]\\underset{x\\to 6}{\\lim}(f(x)+\\frac{1}{3}g(x))[\/latex]<\/p>\r\n[reveal-answer q=\"fs-id1170572480532\"]Show Solution[\/reveal-answer]\r\n[hidden-answer a=\"fs-id1170572480532\"]\r\n<p id=\"fs-id1170572480532\">[latex]\\underset{x\\to 6}{\\lim}(f(x)+\\frac{1}{3}g(x))=\\underset{x\\to 6}{\\lim}f(x)+\\frac{1}{3}\\underset{x\\to 6}{\\lim}g(x)=7[\/latex]<\/p>\r\n[\/hidden-answer]\r\n\r\n<\/div>\r\n<\/div>\r\n<div id=\"fs-id1170572243205\" class=\"exercise\">\r\n<div id=\"fs-id1170572243208\" class=\"textbox\">\r\n<p id=\"fs-id1170572243210\"><strong>28.\u00a0<\/strong>[latex]\\underset{x\\to 6}{\\lim}\\dfrac{(h(x))^3}{2}[\/latex]<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<div id=\"fs-id1170572243346\" class=\"exercise\">\r\n<div id=\"fs-id1170572217321\" class=\"textbox\">\r\n<p id=\"fs-id1170572217323\"><strong>29.\u00a0<\/strong>[latex]\\underset{x\\to 6}{\\lim}\\sqrt{g(x)-f(x)}[\/latex]<\/p>\r\n[reveal-answer q=\"fs-id1170572217368\"]Show Solution[\/reveal-answer]\r\n[hidden-answer a=\"fs-id1170572217368\"]\r\n<p id=\"fs-id1170572217368\">[latex]\\underset{x\\to 6}{\\lim}\\sqrt{g(x)-f(x)}=\\sqrt{\\underset{x\\to 6}{\\lim}g(x)-\\underset{x\\to 6}{\\lim}f(x)}=\\sqrt{5}[\/latex]<\/p>\r\n[\/hidden-answer]\r\n\r\n<\/div>\r\n<\/div>\r\n<div id=\"fs-id1170572217470\" class=\"exercise\">\r\n<div id=\"fs-id1170572217472\" class=\"textbox\">\r\n<p id=\"fs-id1170572217474\"><strong>30.\u00a0<\/strong>[latex]\\underset{x\\to 6}{\\lim}x \\cdot h(x)[\/latex]<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<div id=\"fs-id1170572549028\" class=\"exercise\">\r\n<div id=\"fs-id1170572549030\" class=\"textbox\">\r\n<p id=\"fs-id1170572549032\"><strong>31.\u00a0<\/strong>[latex]\\underset{x\\to 6}{\\lim}[(x+1)\\cdot f(x)][\/latex]<\/p>\r\n[reveal-answer q=\"fs-id1170572549082\"]Show Solution[\/reveal-answer]\r\n[hidden-answer a=\"fs-id1170572549082\"][latex]\\underset{x\\to 6}{\\lim}[(x+1)\\cdot f(x)]=(\\underset{x\\to 6}{\\lim}(x+1))(\\underset{x\\to 6}{\\lim}f(x))=28[\/latex].\r\n[\/hidden-answer]\r\n\r\n<\/div>\r\n<\/div>\r\n<div class=\"textbox\"><strong>32.\u00a0<\/strong>[latex]\\underset{x\\to 6}{\\lim}(f(x)\\cdot g(x)-h(x))[\/latex]<\/div>\r\nIn the following exercises (33-35), use a calculator to draw the graph of each piecewise-defined function and study the graph to evaluate the given limits.\r\n<div id=\"fs-id1170572624112\" class=\"exercise\">\r\n<div class=\"textbox\">\r\n\r\n<strong>33. [T]\u00a0<\/strong>[latex]f(x)=\\begin{cases} x^2, &amp; x \\le 3 \\\\ x+4, &amp; x &gt; 3 \\end{cases}[\/latex]\r\n<ol id=\"fs-id1170572624178\" style=\"list-style-type: lower-alpha;\">\r\n \t<li>[latex]\\underset{x\\to 3^-}{\\lim}f(x)[\/latex]<\/li>\r\n \t<li>[latex]\\underset{x\\to 3^+}{\\lim}f(x)[\/latex]<\/li>\r\n<\/ol>\r\n[reveal-answer q=\"fs-id1170572624250\"]Show Solution[\/reveal-answer]\r\n[hidden-answer a=\"fs-id1170572624250\"]<span id=\"fs-id1170572380891\"><img class=\"aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/2332\/2018\/01\/11203448\/CNX_Calc_Figure_02_03_202.jpg\" alt=\"The graph of a piecewise function with two segments. The first is the parabola x^2, which exists for x&lt;=3. The vertex is at the origin, it opens upward, and there is a closed circle at the endpoint (3,9). The second segment is the line x+4, which is a linear function existing for x &gt; 3. There is an open circle at (3, 7), and the slope is 1.\" \/><\/span>\r\na. 9; b. 7[\/hidden-answer]\r\n\r\n<\/div>\r\n<\/div>\r\n<div id=\"fs-id1170572380907\" class=\"exercise\">\r\n<div id=\"fs-id1170572380909\" class=\"textbox\">\r\n<p id=\"fs-id1170572380911\"><strong>34. [T]\u00a0<\/strong>[latex]g(x)=\\begin{cases} x^3 - 1, &amp; x \\le 0 \\\\ 1, &amp; x &gt; 0 \\end{cases}[\/latex]<\/p>\r\n\r\n<ol id=\"fs-id1170572380974\" style=\"list-style-type: lower-alpha;\">\r\n \t<li>[latex]\\underset{x\\to 0^-}{\\lim}g(x)[\/latex]<\/li>\r\n \t<li>[latex]\\underset{x\\to 0^+}{\\lim}g(x)[\/latex]<\/li>\r\n<\/ol>\r\n<\/div>\r\n<\/div>\r\n<div id=\"fs-id1170572381069\" class=\"exercise\">\r\n<div id=\"fs-id1170572381071\" class=\"textbox\">\r\n<p id=\"fs-id1170572381073\"><strong>35. [T]\u00a0<\/strong>[latex]h(x)=\\begin{cases} x^2-2x+1, &amp; x &lt; 2 \\\\ 3 - x, &amp; x \\ge 2 \\end{cases}[\/latex]<\/p>\r\n\r\n<ol style=\"list-style-type: lower-alpha;\">\r\n \t<li style=\"list-style-type: none;\">\r\n<ol style=\"list-style-type: lower-alpha;\">\r\n \t<li>[latex]\\underset{x\\to 2^-}{\\lim}h(x)[\/latex]<\/li>\r\n \t<li>[latex]\\underset{x\\to 2^+}{\\lim}h(x)[\/latex]<\/li>\r\n<\/ol>\r\n<\/li>\r\n<\/ol>\r\n[reveal-answer q=\"fs-id1170572268044\"]Show Solution[\/reveal-answer]\r\n[hidden-answer a=\"fs-id1170572268044\"]<span id=\"fs-id1170572268051\"><img class=\"aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/2332\/2018\/01\/11203451\/CNX_Calc_Figure_02_03_204.jpg\" alt=\"The graph of a piecewise function with two segments. The first segment is the parabola x^2 \u2013 2x + 1, for x &lt; 2. It opens upward and has a vertex at (1,0). The second segment is the line 3-x for x&gt;= 2. It has a slope of -1 and an x intercept at (3,0).\" \/><\/span>\r\na. 1; b. 1[\/hidden-answer]\r\n\r\n<\/div>\r\n<\/div>\r\n<p id=\"fs-id1170572268067\">In the following exercises (36-43), use the graphs below and the limit laws to evaluate each limit.<\/p>\r\n<span id=\"fs-id1170572268078\"><img class=\"aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/2332\/2018\/01\/11203454\/CNX_Calc_Figure_02_03_201.jpg\" alt=\"Two graphs of piecewise functions. The upper is f(x), which has two linear segments. The first is a line with negative slope existing for x &lt; -3. It goes toward the point (-3,0) at x= -3. The next has increasing slope and goes to the point (-3,-2) at x=-3. It exists for x &gt; -3. Other key points are (0, 1), (-5,2), (1,2), (-7, 4), and (-9,6). The lower piecewise function has a linear segment and a curved segment. The linear segment exists for x &lt; -3 and has decreasing slope. It goes to (-3,-2) at x=-3. The curved segment appears to be the right half of a downward opening parabola. It goes to the vertex point (-3,2) at x=-3. It crosses the y axis a little below y=-2. Other key points are (0, -7\/3), (-5,0), (1,-5), (-7, 2), and (-9, 4).\" \/><\/span>\r\n<div id=\"fs-id1170572268090\" class=\"exercise\">\r\n<div id=\"fs-id1170572268092\" class=\"textbox\">\r\n<p id=\"fs-id1170572268094\"><strong>36.\u00a0<\/strong>[latex]\\underset{x\\to -3^+}{\\lim}(f(x)+g(x))[\/latex]<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<div id=\"fs-id1170571690335\" class=\"exercise\">\r\n<div id=\"fs-id1170571690337\" class=\"textbox\">\r\n<p id=\"fs-id1170571690339\"><strong>37.\u00a0<\/strong>[latex]\\underset{x\\to -3^-}{\\lim}(f(x)-3g(x))[\/latex]<\/p>\r\n[reveal-answer q=\"fs-id1170572434876\"]Show Solution[\/reveal-answer]\r\n[hidden-answer a=\"fs-id1170572434876\"]\r\n<p id=\"fs-id1170572434876\">[latex]\\underset{x\\to -3^-}{\\lim}(f(x)-3g(x))=\\underset{x\\to -3^-}{\\lim}f(x)-3\\underset{x\\to -3^-}{\\lim}g(x)=0+6=6[\/latex]<\/p>\r\n[\/hidden-answer]\r\n\r\n<\/div>\r\n<\/div>\r\n<div id=\"fs-id1170572435008\" class=\"exercise\">\r\n<div id=\"fs-id1170572435010\" class=\"textbox\">\r\n<p id=\"fs-id1170572435012\"><strong>38.\u00a0<\/strong>[latex]\\underset{x\\to 0}{\\lim}\\dfrac{f(x)g(x)}{3}[\/latex]<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<div class=\"exercise\">\r\n<div id=\"fs-id1170572219520\" class=\"textbox\">\r\n<p id=\"fs-id1170572219522\"><strong>39.\u00a0<\/strong>[latex]\\underset{x\\to -5}{\\lim}\\dfrac{2+g(x)}{f(x)}[\/latex]<\/p>\r\n[reveal-answer q=\"fs-id1170572219572\"]Show Solution[\/reveal-answer]\r\n[hidden-answer a=\"fs-id1170572219572\"]\r\n<p id=\"fs-id1170572219572\">[latex]\\underset{x\\to -5}{\\lim}\\frac{2+g(x)}{f(x)}=\\frac{2+(\\underset{x\\to -5}{\\lim}g(x))}{\\underset{x\\to -5}{\\lim}f(x)}=\\frac{2+0}{2}=1[\/latex]<\/p>\r\n[\/hidden-answer]\r\n\r\n<\/div>\r\n<\/div>\r\n<div id=\"fs-id1170572590096\" class=\"exercise\">\r\n<div id=\"fs-id1170572590098\" class=\"textbox\">\r\n<p id=\"fs-id1170572590100\"><strong>40.\u00a0<\/strong>[latex]\\underset{x\\to 1}{\\lim}(f(x))^2[\/latex]<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<div id=\"fs-id1170572552593\" class=\"exercise\">\r\n<div id=\"fs-id1170572552595\" class=\"textbox\">\r\n<p id=\"fs-id1170572552597\"><strong>41.\u00a0<\/strong>[latex]\\underset{x\\to 1}{\\lim}\\sqrt[3]{f(x)-g(x)}[\/latex]<\/p>\r\n[reveal-answer q=\"957757\"]Show Solution[\/reveal-answer]\r\n[hidden-answer a=\"957757\"]\r\n[latex]\\underset{x\\to 1}{\\lim}\\sqrt[3]{f(x)-g(x)}=\\sqrt[3]{\\underset{x\\to 1}{\\lim}f(x)-\\underset{x\\to 1}{\\lim}g(x)}=\\sqrt[3]{2+5}=\\sqrt[3]{7}[\/latex]\r\n[\/hidden-answer]\r\n\r\n<\/div>\r\n<\/div>\r\n<div id=\"fs-id1170572128651\" class=\"exercise\">\r\n<div id=\"fs-id1170572128653\" class=\"textbox\">\r\n<p id=\"fs-id1170572128656\"><strong>42.\u00a0<\/strong>[latex]\\underset{x\\to -7}{\\lim}(x \\cdot g(x))[\/latex]<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<div id=\"fs-id1170572128832\" class=\"exercise\">\r\n<div id=\"fs-id1170572128834\" class=\"textbox\">\r\n\r\n<strong>43.\u00a0<\/strong>[latex]\\underset{x\\to -9}{\\lim}[xf(x)+2g(x)][\/latex]\r\n\r\n[reveal-answer q=\"fs-id1170572540774\"]Show Solution[\/reveal-answer]\r\n[hidden-answer a=\"fs-id1170572540774\"]\r\n<p id=\"fs-id1170572540774\">[latex]\\underset{x\\to -9}{\\lim}(x\\cdot f(x)+2g(x))=(\\underset{x\\to -9}{\\lim}x)(\\underset{x\\to -9}{\\lim}f(x))+2\\underset{x\\to -9}{\\lim}(g(x))=(-9)(6)+2(4)=-46[\/latex]<\/p>\r\n[\/hidden-answer]\r\n\r\n<\/div>\r\n<p id=\"fs-id1170572511239\">For the following problems (44-46), evaluate the limit using the Squeeze Theorem. Use a calculator to graph the functions [latex]f(x), \\, g(x)[\/latex], and [latex]h(x)[\/latex] when possible.<\/p>\r\n\r\n<div id=\"fs-id1170572511282\" class=\"exercise\">\r\n<div id=\"fs-id1170572511284\" class=\"textbox\">\r\n<p id=\"fs-id1170572511286\"><strong>44. [T]<\/strong> True or False? If [latex]2x-1\\le g(x)\\le x^2-2x+3[\/latex], then [latex]\\underset{x\\to 2}{\\lim}g(x)=0[\/latex].<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<div id=\"fs-id1170572511389\" class=\"exercise\">\r\n<div id=\"fs-id1170572511391\" class=\"textbox\">\r\n<p id=\"fs-id1170572511393\"><strong>45. [T]\u00a0<\/strong>[latex]\\underset{\\theta \\to 0}{\\lim}\\theta^2 \\cos\\left(\\frac{1}{\\theta}\\right)[\/latex]<\/p>\r\n[reveal-answer q=\"fs-id1170571625945\"]Show Solution[\/reveal-answer]\r\n[hidden-answer a=\"fs-id1170571625945\"]\r\n<p id=\"fs-id1170571625945\">The limit is zero.<\/p>\r\n<span id=\"fs-id1170571625949\"><img class=\"aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/2332\/2018\/01\/11203457\/CNX_Calc_Figure_02_03_206.jpg\" alt=\"The graph of three functions over the domain [-1,1], colored red, green, and blue as follows: red: theta^2, green: theta^2 * cos (1\/theta), and blue: - (theta^2). The red and blue functions open upwards and downwards respectively as parabolas with vertices at the origin. The green function is trapped between the two.\" \/><\/span>[\/hidden-answer]\r\n\r\n<\/div>\r\n<\/div>\r\n<div id=\"fs-id1170571625966\" class=\"exercise\">\r\n<div id=\"fs-id1170571625968\" class=\"textbox\">\r\n<p id=\"fs-id1170571625970\"><strong>46.\u00a0<\/strong>[latex]\\underset{x\\to 0}{\\lim}f(x)[\/latex], where [latex]f(x)=\\begin{cases} 0, &amp; x \\, \\text{rational} \\\\ x^2, &amp; x \\, \\text{irrational} \\end{cases}[\/latex]<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<div id=\"fs-id1170571626094\" class=\"exercise\">\r\n<div id=\"fs-id1170571626096\" class=\"textbox\">\r\n<p id=\"fs-id1170571626098\"><strong>47. [T]<\/strong> In physics, the magnitude of an electric field generated by a point charge at a distance [latex]r[\/latex] in vacuum is governed by Coulomb\u2019s law: [latex]E(r)=\\large \\frac{q}{4\\pi \\varepsilon_0 r^2}[\/latex], where [latex]E[\/latex] represents the magnitude of the electric field, [latex]q[\/latex] is the charge of the particle, [latex]r[\/latex] is the distance between the particle and where the strength of the field is measured, and [latex]\\large \\frac{1}{4\\pi \\varepsilon_0}[\/latex] is Coulomb\u2019s constant: [latex]8.988 \\times 10^9 \\, \\text{N} \\cdot \\text{m}^2\/\\text{C}^2[\/latex].<\/p>\r\n\r\n<ol id=\"fs-id1170571612177\" style=\"list-style-type: lower-alpha;\">\r\n \t<li>Use a graphing calculator to graph [latex]E(r)[\/latex] given that the charge of the particle is [latex]q=10^{-10}[\/latex].<\/li>\r\n \t<li>Evaluate [latex]\\underset{r\\to 0^+}{\\lim}E(r)[\/latex]. What is the physical meaning of this quantity? Is it physically relevant? Why are you evaluating from the right?<\/li>\r\n<\/ol>\r\n[reveal-answer q=\"fs-id1170571612256\"]Show Solution[\/reveal-answer]\r\n[hidden-answer a=\"fs-id1170571612256\"]\r\n<p id=\"fs-id1170571612256\">a.<\/p>\r\n<span id=\"fs-id1170571612260\"><img class=\"aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/2332\/2018\/01\/11203459\/CNX_Calc_Figure_02_03_207-1.jpg\" alt=\"A graph of a function with two curves. The first is in quadrant two and curves asymptotically to infinity along the y axis and to 0 along the x axis as x goes to negative infinity. The second is in quadrant one and curves asymptotically to infinity along the y axis and to 0 along the x axis as x goes to infinity.\" \/><\/span>\r\nb. [latex]\\underset{r\\to 0^+}{\\lim}E(r)=\\infty[\/latex]. The magnitude of the electric field as you approach the particle [latex]q[\/latex] becomes infinite. It does not make physical sense to evaluate negative distance.[\/hidden-answer]\r\n\r\n<\/div>\r\n<\/div>\r\n<div id=\"fs-id1170571612287\" class=\"exercise\">\r\n<div id=\"fs-id1170571612289\" class=\"textbox\">\r\n<p id=\"fs-id1170571612291\"><strong>48. [T]<\/strong> The density of an object is given by its mass divided by its volume: [latex]\\rho =\\dfrac{m}{V}[\/latex].<\/p>\r\n\r\n<ol id=\"fs-id1170572512567\" style=\"list-style-type: lower-alpha;\">\r\n \t<li>Use a calculator to plot the volume as a function of density [latex](V=\\frac{m}{\\rho})[\/latex], assuming you are examining something of mass 8 kg ([latex]m=8[\/latex]).<\/li>\r\n \t<li>Evaluate [latex]\\underset{\\rho \\to 0^+}{\\lim}V(\\rho)[\/latex] and explain the physical meaning.<\/li>\r\n<\/ol>\r\n<\/div>\r\n<\/div>\r\n<\/div>","rendered":"<p id=\"fs-id1170572597920\">In the following exercises (1-4), use the limit laws to evaluate each limit. Justify each step by indicating the appropriate limit law(s).<\/p>\n<div id=\"fs-id1170572597924\" class=\"exercise\">\n<div id=\"fs-id1170572597926\" class=\"textbox\">\n<p id=\"fs-id1170572597929\"><strong>1.\u00a0<\/strong>[latex]\\underset{x\\to 0}{\\lim}(4x^2-2x+3)[\/latex]<\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"qfs-id1170572597974\">Show Solution<\/span><\/p>\n<div id=\"qfs-id1170572597974\" class=\"hidden-answer\" style=\"display: none\">\n<p id=\"fs-id1170572597974\">Use constant multiple law and difference law: [latex]\\underset{x\\to 0}{\\lim}(4x^2-2x+3)=4\\underset{x\\to 0}{\\lim}x^2-2\\underset{x\\to 0}{\\lim}x+\\underset{x\\to 0}{\\lim}3=3[\/latex]<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<div id=\"fs-id1170572347613\" class=\"exercise\">\n<div id=\"fs-id1170572347616\" class=\"textbox\">\n<p id=\"fs-id1170572347618\"><strong>2.\u00a0<\/strong>[latex]\\underset{x\\to 1}{\\lim}\\frac{x^3+3x^2+5}{4-7x}[\/latex]<\/p>\n<\/div>\n<\/div>\n<div id=\"fs-id1170571574688\" class=\"exercise\">\n<div id=\"fs-id1170571574690\" class=\"textbox\">\n<p id=\"fs-id1170571574692\"><strong>3.\u00a0<\/strong>[latex]\\underset{x\\to -2}{\\lim}\\sqrt{x^2-6x+3}[\/latex]<\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"qfs-id1170571574734\">Show Solution<\/span><\/p>\n<div id=\"qfs-id1170571574734\" class=\"hidden-answer\" style=\"display: none\">\n<p id=\"fs-id1170571574734\">Use root law: [latex]\\underset{x\\to -2}{\\lim}\\sqrt{x^2-6x+3}=\\sqrt{\\underset{x\\to -2}{\\lim}(x^2-6x+3)}=\\sqrt{19}[\/latex]<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<div id=\"fs-id1170572229064\" class=\"exercise\">\n<div id=\"fs-id1170572229066\" class=\"textbox\">\n<p><strong>4.\u00a0<\/strong>[latex]\\underset{x\\to -1}{\\lim}(9x+1)^2[\/latex]<\/p>\n<\/div>\n<\/div>\n<p id=\"fs-id1170572229201\">In the following exercises (5-10), use direct substitution to evaluate each limit.<\/p>\n<div id=\"fs-id1170572229204\" class=\"exercise\">\n<div id=\"fs-id1170572229206\" class=\"textbox\">\n<p id=\"fs-id1170572229209\"><strong>5.\u00a0<\/strong>[latex]\\underset{x\\to 7}{\\lim}x^2[\/latex]<\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"qfs-id1170571654822\">Show Solution<\/span><\/p>\n<div id=\"qfs-id1170571654822\" class=\"hidden-answer\" style=\"display: none\">\n<p id=\"fs-id1170571654822\">49<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<div id=\"fs-id1170571654827\" class=\"exercise\">\n<div id=\"fs-id1170571654830\" class=\"textbox\">\n<p id=\"fs-id1170571654832\"><strong>6.\u00a0<\/strong>[latex]\\underset{x\\to -2}{\\lim}(4x^2-1)[\/latex]<\/p>\n<\/div>\n<\/div>\n<div id=\"fs-id1170571654878\" class=\"exercise\">\n<div id=\"fs-id1170571654880\" class=\"textbox\">\n<p id=\"fs-id1170571654882\"><strong>7.\u00a0<\/strong>[latex]\\underset{x\\to 0}{\\lim}\\dfrac{1}{1+ \\sin x}[\/latex]<\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"qfs-id1170571654916\">Show Solution<\/span><\/p>\n<div id=\"qfs-id1170571654916\" class=\"hidden-answer\" style=\"display: none\">\n<p id=\"fs-id1170571654916\">1<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<div id=\"fs-id1170571654921\" class=\"exercise\">\n<div id=\"fs-id1170571654923\" class=\"textbox\">\n<p id=\"fs-id1170571654925\"><strong>8.\u00a0<\/strong>[latex]\\underset{x\\to 2}{\\lim}e^{2x-x^2}[\/latex]<\/p>\n<\/div>\n<\/div>\n<div id=\"fs-id1170571654968\" class=\"exercise\">\n<div id=\"fs-id1170571654970\" class=\"textbox\">\n<p id=\"fs-id1170571654972\"><strong>9.\u00a0<\/strong>[latex]\\underset{x\\to 1}{\\lim}\\dfrac{2-7x}{x+6}[\/latex]<\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"qfs-id1170572482577\">Show Solution<\/span><\/p>\n<div id=\"qfs-id1170572482577\" class=\"hidden-answer\" style=\"display: none\">\n<p id=\"fs-id1170572482577\">[latex]-\\frac{5}{7}[\/latex]<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<div id=\"fs-id1170572482590\" class=\"exercise\">\n<div id=\"fs-id1170572482593\" class=\"textbox\">\n<p id=\"fs-id1170572482595\"><strong>10.\u00a0<\/strong>[latex]\\underset{x\\to 3}{\\lim}\\ln e^{3x}[\/latex]<\/p>\n<\/div>\n<\/div>\n<p id=\"fs-id1170572482632\">In the following exercises (11-20), use direct substitution to show that each limit leads to the indeterminate form [latex]\\frac{0}{0}[\/latex]. Then, evaluate the limit.<\/p>\n<div id=\"fs-id1170572482649\" class=\"exercise\">\n<div id=\"fs-id1170572482652\" class=\"textbox\">\n<p id=\"fs-id1170572482654\"><strong>11.\u00a0<\/strong>[latex]\\underset{x\\to 4}{\\lim}\\dfrac{x^2-16}{x-4}[\/latex]<\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"qfs-id1170572482694\">Show Solution<\/span><\/p>\n<div id=\"qfs-id1170572482694\" class=\"hidden-answer\" style=\"display: none\">\n<p id=\"fs-id1170572482694\">[latex]\\underset{x\\to 4}{\\lim}\\frac{x^2-16}{x-4}=\\frac{16-16}{4-4}=\\frac{0}{0}[\/latex]; then, [latex]\\underset{x\\to 4}{\\lim}\\frac{x^2-16}{x-4}=\\underset{x\\to 4}{\\lim}\\frac{(x+4)(x-4)}{x-4}=8[\/latex]<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<div id=\"fs-id1170572403294\" class=\"exercise\">\n<div id=\"fs-id1170572403296\" class=\"textbox\">\n<p id=\"fs-id1170572403299\"><strong>12.\u00a0<\/strong>[latex]\\underset{x\\to 2}{\\lim}\\dfrac{x-2}{x^2-2x}[\/latex]<\/p>\n<\/div>\n<\/div>\n<div id=\"fs-id1170571586166\" class=\"exercise\">\n<div id=\"fs-id1170571586168\" class=\"textbox\">\n<p id=\"fs-id1170571586170\"><strong>13.\u00a0<\/strong>[latex]\\underset{x\\to 6}{\\lim}\\dfrac{3x-18}{2x-12}[\/latex]<\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"qfs-id1170571586209\">Show Solution<\/span><\/p>\n<div id=\"qfs-id1170571586209\" class=\"hidden-answer\" style=\"display: none\">[latex]\\underset{x\\to 6}{\\lim}\\frac{3x-18}{2x-12}=\\frac{18-18}{12-12}=\\frac{0}{0}[\/latex]; then, [latex]\\underset{x\\to 6}{\\lim}\\frac{3x-18}{2x-12}=\\underset{x\\to 6}{\\lim}\\frac{3(x-6)}{2(x-6)}=\\frac{3}{2}[\/latex]\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<div id=\"fs-id1170572503561\" class=\"exercise\">\n<div id=\"fs-id1170572503563\" class=\"textbox\">\n<p id=\"fs-id1170572503565\"><strong>14.\u00a0<\/strong>[latex]\\underset{h\\to 0}{\\lim}\\dfrac{(1+h)^2-1}{h}[\/latex]<\/p>\n<\/div>\n<\/div>\n<div id=\"fs-id1170572499899\" class=\"exercise\">\n<div id=\"fs-id1170572499901\" class=\"textbox\">\n<p id=\"fs-id1170572499903\"><strong>15.\u00a0<\/strong>[latex]\\underset{t\\to 9}{\\lim}\\dfrac{t-9}{\\sqrt{t}-3}[\/latex]<\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"qfs-id1170572499942\">Show Solution<\/span><\/p>\n<div id=\"qfs-id1170572499942\" class=\"hidden-answer\" style=\"display: none\">\n<p id=\"fs-id1170572499942\">[latex]\\underset{t \\to 9}{\\lim}\\frac{t-9}{\\sqrt{t}-3}=\\frac{9-9}{3-3}=\\frac{0}{0}[\/latex]; then, [latex]\\underset{t\\to 9}{\\lim}\\frac{t-9}{\\sqrt{t}-3}=\\underset{t\\to 9}{\\lim}\\frac{t-9}{\\sqrt{t}-3}\\frac{\\sqrt{t}+3}{\\sqrt{t}+3}=\\underset{t\\to 9}{\\lim}(\\sqrt{t}+3)=6[\/latex]<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<div id=\"fs-id1170571655854\" class=\"exercise\">\n<div id=\"fs-id1170571655856\" class=\"textbox\">\n<p id=\"fs-id1170571655859\"><strong>16.\u00a0<\/strong>[latex]\\underset{h\\to 0}{\\lim}\\dfrac{\\frac{1}{a+h}-\\frac{1}{a}}{h}[\/latex], where [latex]a[\/latex] is a real-valued constant<\/p>\n<\/div>\n<\/div>\n<div id=\"fs-id1170571657390\" class=\"exercise\">\n<div id=\"fs-id1170571657392\" class=\"textbox\">\n<p id=\"fs-id1170571657395\"><strong>17.\u00a0<\/strong>[latex]\\underset{\\theta \\to \\pi}{\\lim}\\dfrac{\\sin \\theta}{\\tan \\theta}[\/latex]<\/p>\n<div id=\"fs-id1170571657390\" class=\"exercise\">\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"qfs-id1170571657432\">Show Solution<\/span><\/p>\n<div id=\"qfs-id1170571657432\" class=\"hidden-answer\" style=\"display: none\">[latex]\\underset{\\theta \\to \\pi}{\\lim}\\frac{\\sin \\theta}{\\tan \\theta}=\\frac{\\sin \\pi}{\\tan \\pi}=\\frac{0}{0}[\/latex]; then, [latex]\\underset{\\theta \\to \\pi}{\\lim}\\frac{\\sin \\theta}{\\tan \\theta}=\\underset{\\theta \\to \\pi}{\\lim}\\frac{\\sin \\theta}{\\frac{\\sin \\theta}{\\cos \\theta}}=\\underset{\\theta \\to \\pi}{\\lim}\\cos \\theta =-1[\/latex].\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<div id=\"fs-id1170571599916\" class=\"exercise\">\n<div id=\"fs-id1170571599918\" class=\"textbox\">\n<p id=\"fs-id1170571599920\"><strong>18.\u00a0<\/strong>[latex]\\underset{x\\to 1}{\\lim}\\dfrac{x^3-1}{x^2-1}[\/latex]<\/p>\n<\/div>\n<\/div>\n<div id=\"fs-id1170572551466\" class=\"exercise\">\n<div id=\"fs-id1170572551468\" class=\"textbox\">\n<p id=\"fs-id1170572551470\"><strong>19.\u00a0<\/strong>[latex]\\underset{x\\to 1\/2}{\\lim}\\dfrac{2x^2+3x-2}{2x-1}[\/latex]<\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"qfs-id1170572551526\">Show Solution<\/span><\/p>\n<div id=\"qfs-id1170572551526\" class=\"hidden-answer\" style=\"display: none\">\n<p id=\"fs-id1170572551526\">[latex]\\underset{x\\to 1\/2}{\\lim}\\frac{2x^2+3x-2}{2x-1}=\\frac{\\frac{1}{2}+\\frac{3}{2}-2}{1-1}=\\frac{0}{0}[\/latex]; then, [latex]\\underset{x\\to 1\/2}{\\lim}\\frac{2x^2+3x-2}{2x-1}=\\underset{x\\to 1\/2}{\\lim}\\frac{(2x-1)(x+2)}{2x-1}=\\frac{5}{2}[\/latex]<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<div id=\"fs-id1170571599675\" class=\"exercise\">\n<div id=\"fs-id1170571599677\" class=\"textbox\">\n<p id=\"fs-id1170571599679\"><strong>20.\u00a0<\/strong>[latex]\\underset{x\\to -3}{\\lim}\\dfrac{\\sqrt{x+4}-1}{x+3}[\/latex]<\/p>\n<\/div>\n<\/div>\n<p id=\"fs-id1170572174650\">In the following exercises (21-24), use direct substitution to obtain an undefined expression. Then, use the method of <a class=\"autogenerated-content\" href=\"#fs-id1170571611196\">(Figure)<\/a> to simplify the function to help determine the limit.<\/p>\n<div id=\"fs-id1170572174658\" class=\"exercise\">\n<div id=\"fs-id1170572174658\" class=\"exercise\">\n<div id=\"fs-id1170572174660\" class=\"textbox\">\n<p id=\"fs-id1170572174662\"><strong>21.\u00a0<\/strong>[latex]\\underset{x\\to -2^-}{\\lim}\\dfrac{2x^2+7x-4}{x^2+x-2}[\/latex]<\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"qfs-id1170572174724\">Show Solution<\/span><\/p>\n<div id=\"qfs-id1170572174724\" class=\"hidden-answer\" style=\"display: none\">\n<p id=\"fs-id1170572174724\">[latex]-\\infty[\/latex]<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<div id=\"fs-id1170572174729\" class=\"exercise\">\n<div id=\"fs-id1170572174731\" class=\"textbox\">\n<p id=\"fs-id1170572174734\"><strong>22.\u00a0<\/strong>[latex]\\underset{x\\to -2^+}{\\lim}\\dfrac{2x^2+7x-4}{x^2+x-2}[\/latex]<\/p>\n<\/div>\n<\/div>\n<div id=\"fs-id1170572174801\" class=\"exercise\">\n<div id=\"fs-id1170572174803\" class=\"textbox\">\n<p id=\"fs-id1170572174805\"><strong>23.\u00a0<\/strong>[latex]\\underset{x\\to 1^-}{\\lim}\\dfrac{2x^2+7x-4}{x^2+x-2}[\/latex]<\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"qfs-id1170571610806\">Show Solution<\/span><\/p>\n<div id=\"qfs-id1170571610806\" class=\"hidden-answer\" style=\"display: none\">\n<p id=\"fs-id1170571610806\">[latex]-\\infty[\/latex]<\/p>\n<\/div>\n<\/div>\n<\/div>\n<div class=\"textbox\"><strong>24. <\/strong>[latex]\\underset{x\\to 1^+}{\\lim}\\dfrac{2x^2+7x-4}{x^2+x-2}[\/latex]<\/div>\n<\/div>\n<\/div>\n<p id=\"fs-id1170571610881\">In the following exercises (25-32), assume that [latex]\\underset{x\\to 6}{\\lim}f(x)=4, \\, \\underset{x\\to 6}{\\lim}g(x)=9[\/latex], and [latex]\\underset{x\\to 6}{\\lim}h(x)=6[\/latex]. Use these three facts and the limit laws to evaluate each limit.<\/p>\n<div id=\"fs-id1170571610978\" class=\"exercise\">\n<div id=\"fs-id1170571610980\" class=\"textbox\">\n<p id=\"fs-id1170571610983\"><strong>25.\u00a0<\/strong>[latex]\\underset{x\\to 6}{\\lim}2f(x)g(x)[\/latex]<\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"qfs-id1170571669784\">Show Solution<\/span><\/p>\n<div id=\"qfs-id1170571669784\" class=\"hidden-answer\" style=\"display: none\">\n<p id=\"fs-id1170571669784\">[latex]\\underset{x\\to 6}{\\lim}2f(x)g(x)=2\\underset{x\\to 6}{\\lim}f(x)\\underset{x\\to 6}{\\lim}g(x)=72[\/latex]<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<div id=\"fs-id1170571669881\" class=\"exercise\">\n<div id=\"fs-id1170571669883\" class=\"textbox\">\n<p id=\"fs-id1170571669885\"><strong>26.\u00a0<\/strong>[latex]\\underset{x\\to 6}{\\lim}\\dfrac{g(x)-1}{f(x)}[\/latex]<\/p>\n<\/div>\n<\/div>\n<div id=\"fs-id1170572480473\" class=\"exercise\">\n<div id=\"fs-id1170572480476\" class=\"textbox\">\n<p id=\"fs-id1170572480478\"><strong>27.\u00a0<\/strong>[latex]\\underset{x\\to 6}{\\lim}(f(x)+\\frac{1}{3}g(x))[\/latex]<\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"qfs-id1170572480532\">Show Solution<\/span><\/p>\n<div id=\"qfs-id1170572480532\" class=\"hidden-answer\" style=\"display: none\">\n<p id=\"fs-id1170572480532\">[latex]\\underset{x\\to 6}{\\lim}(f(x)+\\frac{1}{3}g(x))=\\underset{x\\to 6}{\\lim}f(x)+\\frac{1}{3}\\underset{x\\to 6}{\\lim}g(x)=7[\/latex]<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<div id=\"fs-id1170572243205\" class=\"exercise\">\n<div id=\"fs-id1170572243208\" class=\"textbox\">\n<p id=\"fs-id1170572243210\"><strong>28.\u00a0<\/strong>[latex]\\underset{x\\to 6}{\\lim}\\dfrac{(h(x))^3}{2}[\/latex]<\/p>\n<\/div>\n<\/div>\n<div id=\"fs-id1170572243346\" class=\"exercise\">\n<div id=\"fs-id1170572217321\" class=\"textbox\">\n<p id=\"fs-id1170572217323\"><strong>29.\u00a0<\/strong>[latex]\\underset{x\\to 6}{\\lim}\\sqrt{g(x)-f(x)}[\/latex]<\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"qfs-id1170572217368\">Show Solution<\/span><\/p>\n<div id=\"qfs-id1170572217368\" class=\"hidden-answer\" style=\"display: none\">\n<p id=\"fs-id1170572217368\">[latex]\\underset{x\\to 6}{\\lim}\\sqrt{g(x)-f(x)}=\\sqrt{\\underset{x\\to 6}{\\lim}g(x)-\\underset{x\\to 6}{\\lim}f(x)}=\\sqrt{5}[\/latex]<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<div id=\"fs-id1170572217470\" class=\"exercise\">\n<div id=\"fs-id1170572217472\" class=\"textbox\">\n<p id=\"fs-id1170572217474\"><strong>30.\u00a0<\/strong>[latex]\\underset{x\\to 6}{\\lim}x \\cdot h(x)[\/latex]<\/p>\n<\/div>\n<\/div>\n<div id=\"fs-id1170572549028\" class=\"exercise\">\n<div id=\"fs-id1170572549030\" class=\"textbox\">\n<p id=\"fs-id1170572549032\"><strong>31.\u00a0<\/strong>[latex]\\underset{x\\to 6}{\\lim}[(x+1)\\cdot f(x)][\/latex]<\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"qfs-id1170572549082\">Show Solution<\/span><\/p>\n<div id=\"qfs-id1170572549082\" class=\"hidden-answer\" style=\"display: none\">[latex]\\underset{x\\to 6}{\\lim}[(x+1)\\cdot f(x)]=(\\underset{x\\to 6}{\\lim}(x+1))(\\underset{x\\to 6}{\\lim}f(x))=28[\/latex].\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<div class=\"textbox\"><strong>32.\u00a0<\/strong>[latex]\\underset{x\\to 6}{\\lim}(f(x)\\cdot g(x)-h(x))[\/latex]<\/div>\n<p>In the following exercises (33-35), use a calculator to draw the graph of each piecewise-defined function and study the graph to evaluate the given limits.<\/p>\n<div id=\"fs-id1170572624112\" class=\"exercise\">\n<div class=\"textbox\">\n<p><strong>33. [T]\u00a0<\/strong>[latex]f(x)=\\begin{cases} x^2, & x \\le 3 \\\\ x+4, & x > 3 \\end{cases}[\/latex]<\/p>\n<ol id=\"fs-id1170572624178\" style=\"list-style-type: lower-alpha;\">\n<li>[latex]\\underset{x\\to 3^-}{\\lim}f(x)[\/latex]<\/li>\n<li>[latex]\\underset{x\\to 3^+}{\\lim}f(x)[\/latex]<\/li>\n<\/ol>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"qfs-id1170572624250\">Show Solution<\/span><\/p>\n<div id=\"qfs-id1170572624250\" class=\"hidden-answer\" style=\"display: none\"><span id=\"fs-id1170572380891\"><img decoding=\"async\" class=\"aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/2332\/2018\/01\/11203448\/CNX_Calc_Figure_02_03_202.jpg\" alt=\"The graph of a piecewise function with two segments. The first is the parabola x^2, which exists for x&lt;=3. The vertex is at the origin, it opens upward, and there is a closed circle at the endpoint (3,9). The second segment is the line x+4, which is a linear function existing for x &gt; 3. There is an open circle at (3, 7), and the slope is 1.\" \/><\/span><br \/>\na. 9; b. 7<\/div>\n<\/div>\n<\/div>\n<\/div>\n<div id=\"fs-id1170572380907\" class=\"exercise\">\n<div id=\"fs-id1170572380909\" class=\"textbox\">\n<p id=\"fs-id1170572380911\"><strong>34. [T]\u00a0<\/strong>[latex]g(x)=\\begin{cases} x^3 - 1, & x \\le 0 \\\\ 1, & x > 0 \\end{cases}[\/latex]<\/p>\n<ol id=\"fs-id1170572380974\" style=\"list-style-type: lower-alpha;\">\n<li>[latex]\\underset{x\\to 0^-}{\\lim}g(x)[\/latex]<\/li>\n<li>[latex]\\underset{x\\to 0^+}{\\lim}g(x)[\/latex]<\/li>\n<\/ol>\n<\/div>\n<\/div>\n<div id=\"fs-id1170572381069\" class=\"exercise\">\n<div id=\"fs-id1170572381071\" class=\"textbox\">\n<p id=\"fs-id1170572381073\"><strong>35. [T]\u00a0<\/strong>[latex]h(x)=\\begin{cases} x^2-2x+1, & x < 2 \\\\ 3 - x, & x \\ge 2 \\end{cases}[\/latex]<\/p>\n<ol style=\"list-style-type: lower-alpha;\">\n<li style=\"list-style-type: none;\">\n<ol style=\"list-style-type: lower-alpha;\">\n<li>[latex]\\underset{x\\to 2^-}{\\lim}h(x)[\/latex]<\/li>\n<li>[latex]\\underset{x\\to 2^+}{\\lim}h(x)[\/latex]<\/li>\n<\/ol>\n<\/li>\n<\/ol>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"qfs-id1170572268044\">Show Solution<\/span><\/p>\n<div id=\"qfs-id1170572268044\" class=\"hidden-answer\" style=\"display: none\"><span id=\"fs-id1170572268051\"><img decoding=\"async\" class=\"aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/2332\/2018\/01\/11203451\/CNX_Calc_Figure_02_03_204.jpg\" alt=\"The graph of a piecewise function with two segments. The first segment is the parabola x^2 \u2013 2x + 1, for x &lt; 2. It opens upward and has a vertex at (1,0). The second segment is the line 3-x for x&gt;= 2. It has a slope of -1 and an x intercept at (3,0).\" \/><\/span><br \/>\na. 1; b. 1<\/div>\n<\/div>\n<\/div>\n<\/div>\n<p id=\"fs-id1170572268067\">In the following exercises (36-43), use the graphs below and the limit laws to evaluate each limit.<\/p>\n<p><span id=\"fs-id1170572268078\"><img decoding=\"async\" class=\"aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/2332\/2018\/01\/11203454\/CNX_Calc_Figure_02_03_201.jpg\" alt=\"Two graphs of piecewise functions. The upper is f(x), which has two linear segments. The first is a line with negative slope existing for x &lt; -3. It goes toward the point (-3,0) at x= -3. The next has increasing slope and goes to the point (-3,-2) at x=-3. It exists for x &gt; -3. Other key points are (0, 1), (-5,2), (1,2), (-7, 4), and (-9,6). The lower piecewise function has a linear segment and a curved segment. The linear segment exists for x &lt; -3 and has decreasing slope. It goes to (-3,-2) at x=-3. The curved segment appears to be the right half of a downward opening parabola. It goes to the vertex point (-3,2) at x=-3. It crosses the y axis a little below y=-2. Other key points are (0, -7\/3), (-5,0), (1,-5), (-7, 2), and (-9, 4).\" \/><\/span><\/p>\n<div id=\"fs-id1170572268090\" class=\"exercise\">\n<div id=\"fs-id1170572268092\" class=\"textbox\">\n<p id=\"fs-id1170572268094\"><strong>36.\u00a0<\/strong>[latex]\\underset{x\\to -3^+}{\\lim}(f(x)+g(x))[\/latex]<\/p>\n<\/div>\n<\/div>\n<div id=\"fs-id1170571690335\" class=\"exercise\">\n<div id=\"fs-id1170571690337\" class=\"textbox\">\n<p id=\"fs-id1170571690339\"><strong>37.\u00a0<\/strong>[latex]\\underset{x\\to -3^-}{\\lim}(f(x)-3g(x))[\/latex]<\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"qfs-id1170572434876\">Show Solution<\/span><\/p>\n<div id=\"qfs-id1170572434876\" class=\"hidden-answer\" style=\"display: none\">\n<p id=\"fs-id1170572434876\">[latex]\\underset{x\\to -3^-}{\\lim}(f(x)-3g(x))=\\underset{x\\to -3^-}{\\lim}f(x)-3\\underset{x\\to -3^-}{\\lim}g(x)=0+6=6[\/latex]<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<div id=\"fs-id1170572435008\" class=\"exercise\">\n<div id=\"fs-id1170572435010\" class=\"textbox\">\n<p id=\"fs-id1170572435012\"><strong>38.\u00a0<\/strong>[latex]\\underset{x\\to 0}{\\lim}\\dfrac{f(x)g(x)}{3}[\/latex]<\/p>\n<\/div>\n<\/div>\n<div class=\"exercise\">\n<div id=\"fs-id1170572219520\" class=\"textbox\">\n<p id=\"fs-id1170572219522\"><strong>39.\u00a0<\/strong>[latex]\\underset{x\\to -5}{\\lim}\\dfrac{2+g(x)}{f(x)}[\/latex]<\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"qfs-id1170572219572\">Show Solution<\/span><\/p>\n<div id=\"qfs-id1170572219572\" class=\"hidden-answer\" style=\"display: none\">\n<p id=\"fs-id1170572219572\">[latex]\\underset{x\\to -5}{\\lim}\\frac{2+g(x)}{f(x)}=\\frac{2+(\\underset{x\\to -5}{\\lim}g(x))}{\\underset{x\\to -5}{\\lim}f(x)}=\\frac{2+0}{2}=1[\/latex]<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<div id=\"fs-id1170572590096\" class=\"exercise\">\n<div id=\"fs-id1170572590098\" class=\"textbox\">\n<p id=\"fs-id1170572590100\"><strong>40.\u00a0<\/strong>[latex]\\underset{x\\to 1}{\\lim}(f(x))^2[\/latex]<\/p>\n<\/div>\n<\/div>\n<div id=\"fs-id1170572552593\" class=\"exercise\">\n<div id=\"fs-id1170572552595\" class=\"textbox\">\n<p id=\"fs-id1170572552597\"><strong>41.\u00a0<\/strong>[latex]\\underset{x\\to 1}{\\lim}\\sqrt[3]{f(x)-g(x)}[\/latex]<\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q957757\">Show Solution<\/span><\/p>\n<div id=\"q957757\" class=\"hidden-answer\" style=\"display: none\">\n[latex]\\underset{x\\to 1}{\\lim}\\sqrt[3]{f(x)-g(x)}=\\sqrt[3]{\\underset{x\\to 1}{\\lim}f(x)-\\underset{x\\to 1}{\\lim}g(x)}=\\sqrt[3]{2+5}=\\sqrt[3]{7}[\/latex]\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<div id=\"fs-id1170572128651\" class=\"exercise\">\n<div id=\"fs-id1170572128653\" class=\"textbox\">\n<p id=\"fs-id1170572128656\"><strong>42.\u00a0<\/strong>[latex]\\underset{x\\to -7}{\\lim}(x \\cdot g(x))[\/latex]<\/p>\n<\/div>\n<\/div>\n<div id=\"fs-id1170572128832\" class=\"exercise\">\n<div id=\"fs-id1170572128834\" class=\"textbox\">\n<p><strong>43.\u00a0<\/strong>[latex]\\underset{x\\to -9}{\\lim}[xf(x)+2g(x)][\/latex]<\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"qfs-id1170572540774\">Show Solution<\/span><\/p>\n<div id=\"qfs-id1170572540774\" class=\"hidden-answer\" style=\"display: none\">\n<p id=\"fs-id1170572540774\">[latex]\\underset{x\\to -9}{\\lim}(x\\cdot f(x)+2g(x))=(\\underset{x\\to -9}{\\lim}x)(\\underset{x\\to -9}{\\lim}f(x))+2\\underset{x\\to -9}{\\lim}(g(x))=(-9)(6)+2(4)=-46[\/latex]<\/p>\n<\/div>\n<\/div>\n<\/div>\n<p id=\"fs-id1170572511239\">For the following problems (44-46), evaluate the limit using the Squeeze Theorem. Use a calculator to graph the functions [latex]f(x), \\, g(x)[\/latex], and [latex]h(x)[\/latex] when possible.<\/p>\n<div id=\"fs-id1170572511282\" class=\"exercise\">\n<div id=\"fs-id1170572511284\" class=\"textbox\">\n<p id=\"fs-id1170572511286\"><strong>44. [T]<\/strong> True or False? If [latex]2x-1\\le g(x)\\le x^2-2x+3[\/latex], then [latex]\\underset{x\\to 2}{\\lim}g(x)=0[\/latex].<\/p>\n<\/div>\n<\/div>\n<div id=\"fs-id1170572511389\" class=\"exercise\">\n<div id=\"fs-id1170572511391\" class=\"textbox\">\n<p id=\"fs-id1170572511393\"><strong>45. [T]\u00a0<\/strong>[latex]\\underset{\\theta \\to 0}{\\lim}\\theta^2 \\cos\\left(\\frac{1}{\\theta}\\right)[\/latex]<\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"qfs-id1170571625945\">Show Solution<\/span><\/p>\n<div id=\"qfs-id1170571625945\" class=\"hidden-answer\" style=\"display: none\">\n<p id=\"fs-id1170571625945\">The limit is zero.<\/p>\n<p><span id=\"fs-id1170571625949\"><img decoding=\"async\" class=\"aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/2332\/2018\/01\/11203457\/CNX_Calc_Figure_02_03_206.jpg\" alt=\"The graph of three functions over the domain [-1,1], colored red, green, and blue as follows: red: theta^2, green: theta^2 * cos (1\/theta), and blue: - (theta^2). The red and blue functions open upwards and downwards respectively as parabolas with vertices at the origin. The green function is trapped between the two.\" \/><\/span><\/div>\n<\/div>\n<\/div>\n<\/div>\n<div id=\"fs-id1170571625966\" class=\"exercise\">\n<div id=\"fs-id1170571625968\" class=\"textbox\">\n<p id=\"fs-id1170571625970\"><strong>46.\u00a0<\/strong>[latex]\\underset{x\\to 0}{\\lim}f(x)[\/latex], where [latex]f(x)=\\begin{cases} 0, & x \\, \\text{rational} \\\\ x^2, & x \\, \\text{irrational} \\end{cases}[\/latex]<\/p>\n<\/div>\n<\/div>\n<div id=\"fs-id1170571626094\" class=\"exercise\">\n<div id=\"fs-id1170571626096\" class=\"textbox\">\n<p id=\"fs-id1170571626098\"><strong>47. [T]<\/strong> In physics, the magnitude of an electric field generated by a point charge at a distance [latex]r[\/latex] in vacuum is governed by Coulomb\u2019s law: [latex]E(r)=\\large \\frac{q}{4\\pi \\varepsilon_0 r^2}[\/latex], where [latex]E[\/latex] represents the magnitude of the electric field, [latex]q[\/latex] is the charge of the particle, [latex]r[\/latex] is the distance between the particle and where the strength of the field is measured, and [latex]\\large \\frac{1}{4\\pi \\varepsilon_0}[\/latex] is Coulomb\u2019s constant: [latex]8.988 \\times 10^9 \\, \\text{N} \\cdot \\text{m}^2\/\\text{C}^2[\/latex].<\/p>\n<ol id=\"fs-id1170571612177\" style=\"list-style-type: lower-alpha;\">\n<li>Use a graphing calculator to graph [latex]E(r)[\/latex] given that the charge of the particle is [latex]q=10^{-10}[\/latex].<\/li>\n<li>Evaluate [latex]\\underset{r\\to 0^+}{\\lim}E(r)[\/latex]. What is the physical meaning of this quantity? Is it physically relevant? Why are you evaluating from the right?<\/li>\n<\/ol>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"qfs-id1170571612256\">Show Solution<\/span><\/p>\n<div id=\"qfs-id1170571612256\" class=\"hidden-answer\" style=\"display: none\">\n<p id=\"fs-id1170571612256\">a.<\/p>\n<p><span id=\"fs-id1170571612260\"><img decoding=\"async\" class=\"aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/2332\/2018\/01\/11203459\/CNX_Calc_Figure_02_03_207-1.jpg\" alt=\"A graph of a function with two curves. The first is in quadrant two and curves asymptotically to infinity along the y axis and to 0 along the x axis as x goes to negative infinity. The second is in quadrant one and curves asymptotically to infinity along the y axis and to 0 along the x axis as x goes to infinity.\" \/><\/span><br \/>\nb. [latex]\\underset{r\\to 0^+}{\\lim}E(r)=\\infty[\/latex]. The magnitude of the electric field as you approach the particle [latex]q[\/latex] becomes infinite. It does not make physical sense to evaluate negative distance.<\/div>\n<\/div>\n<\/div>\n<\/div>\n<div id=\"fs-id1170571612287\" class=\"exercise\">\n<div id=\"fs-id1170571612289\" class=\"textbox\">\n<p id=\"fs-id1170571612291\"><strong>48. [T]<\/strong> The density of an object is given by its mass divided by its volume: [latex]\\rho =\\dfrac{m}{V}[\/latex].<\/p>\n<ol id=\"fs-id1170572512567\" style=\"list-style-type: lower-alpha;\">\n<li>Use a calculator to plot the volume as a function of density [latex](V=\\frac{m}{\\rho})[\/latex], assuming you are examining something of mass 8 kg ([latex]m=8[\/latex]).<\/li>\n<li>Evaluate [latex]\\underset{\\rho \\to 0^+}{\\lim}V(\\rho)[\/latex] and explain the physical meaning.<\/li>\n<\/ol>\n<\/div>\n<\/div>\n<\/div>\n\n\t\t\t <section class=\"citations-section\" role=\"contentinfo\">\n\t\t\t <h3>Candela Citations<\/h3>\n\t\t\t\t\t <div>\n\t\t\t\t\t\t <div id=\"citation-list-457\">\n\t\t\t\t\t\t\t <div class=\"licensing\"><div class=\"license-attribution-dropdown-subheading\">CC licensed content, Shared previously<\/div><ul class=\"citation-list\"><li>Calculus Volume 1. <strong>Authored by<\/strong>: Gilbert Strang, Edwin (Jed) Herman. <strong>Provided by<\/strong>: OpenStax. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"https:\/\/openstax.org\/details\/books\/calculus-volume-1\">https:\/\/openstax.org\/details\/books\/calculus-volume-1<\/a>. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/4.0\/\">CC BY-NC-SA: Attribution-NonCommercial-ShareAlike<\/a><\/em>. <strong>License Terms<\/strong>: Access for free at https:\/\/openstax.org\/books\/calculus-volume-1\/pages\/1-introduction<\/li><\/ul><\/div>\n\t\t\t\t\t\t <\/div>\n\t\t\t\t\t <\/div>\n\t\t\t <\/section>","protected":false},"author":17533,"menu_order":5,"template":"","meta":{"_candela_citation":"[{\"type\":\"cc\",\"description\":\"Calculus Volume 1\",\"author\":\"Gilbert Strang, Edwin (Jed) Herman\",\"organization\":\"OpenStax\",\"url\":\"https:\/\/openstax.org\/details\/books\/calculus-volume-1\",\"project\":\"\",\"license\":\"cc-by-nc-sa\",\"license_terms\":\"Access for free at https:\/\/openstax.org\/books\/calculus-volume-1\/pages\/1-introduction\"}]","CANDELA_OUTCOMES_GUID":"","pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"class_list":["post-457","chapter","type-chapter","status-publish","hentry"],"part":229,"_links":{"self":[{"href":"https:\/\/courses.lumenlearning.com\/calculus1\/wp-json\/pressbooks\/v2\/chapters\/457","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/courses.lumenlearning.com\/calculus1\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/courses.lumenlearning.com\/calculus1\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/calculus1\/wp-json\/wp\/v2\/users\/17533"}],"version-history":[{"count":20,"href":"https:\/\/courses.lumenlearning.com\/calculus1\/wp-json\/pressbooks\/v2\/chapters\/457\/revisions"}],"predecessor-version":[{"id":4515,"href":"https:\/\/courses.lumenlearning.com\/calculus1\/wp-json\/pressbooks\/v2\/chapters\/457\/revisions\/4515"}],"part":[{"href":"https:\/\/courses.lumenlearning.com\/calculus1\/wp-json\/pressbooks\/v2\/parts\/229"}],"metadata":[{"href":"https:\/\/courses.lumenlearning.com\/calculus1\/wp-json\/pressbooks\/v2\/chapters\/457\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/courses.lumenlearning.com\/calculus1\/wp-json\/wp\/v2\/media?parent=457"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/calculus1\/wp-json\/pressbooks\/v2\/chapter-type?post=457"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/calculus1\/wp-json\/wp\/v2\/contributor?post=457"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/calculus1\/wp-json\/wp\/v2\/license?post=457"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}