{"id":12200,"date":"2015-08-17T20:52:57","date_gmt":"2015-08-17T20:52:57","guid":{"rendered":"https:\/\/courses.candelalearning.com\/osprecalc\/?post_type=chapter&p=12200"},"modified":"2019-09-09T21:31:15","modified_gmt":"2019-09-09T21:31:15","slug":"exponential-and-logarithmic-functions-practice-test","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/precalculus\/chapter\/exponential-and-logarithmic-functions-practice-test\/","title":{"raw":"Exponential and Logarithmic Functions Practice Test","rendered":"Exponential and Logarithmic Functions Practice Test"},"content":{"raw":"1. The population of a pod of bottlenose dolphins is modeled by the function [latex]A\\left(t\\right)=8{\\left(1.17\\right)}^{t}[\/latex], where t<\/em>\u00a0is given in years. To the nearest whole number, what will the pod population be after 3\u00a0years?\r\n\r\n2.\u00a0Find an exponential equation that passes through the points (0, 4) and (2, 9).\r\n\r\n3. Drew wants to save $2,500 to go to the next World Cup. To the nearest dollar, how much will he need to invest in an account now with 6.25% APR, compounding daily, in order to reach his goal in 4\u00a0years?\r\n\r\n4.\u00a0An investment account was opened with an initial deposit of $9,600 and earns 7.4% interest, compounded continuously. How much will the account be worth after 15 years?\r\n\r\n5. Graph the function [latex]f\\left(x\\right)=5{\\left(0.5\\right)}^{-x}[\/latex] and its reflection across the y<\/em>-axis on the same axes, and give the y<\/em>-intercept.\r\n\r\n6. The graph shows transformations of the graph of [latex]f\\left(x\\right)={\\left(\\frac{1}{2}\\right)}^{x}[\/latex]. What is the equation for the transformation?\r\n\r\n\"Graph\r\n\r\n7.\u00a0Rewrite [latex]{\\mathrm{log}}_{8.5}\\left(614.125\\right)=a[\/latex] as an equivalent exponential equation.\r\n\r\n8.\u00a0Rewrite [latex]{e}^{\\frac{1}{2}}=m[\/latex] as an equivalent logarithmic equation.\r\n\r\n9. Solve for x<\/em>\u00a0by converting the logarithmic equation [latex]log_{\\frac{1}{7}}\\left(x\\right)=2[\/latex] to exponential form.\r\n\r\n10.\u00a0Evaluate [latex]\\mathrm{log}\\left(\\text{10,000,000}\\right)[\/latex] without using a calculator.\r\n\r\n11. Evaluate [latex]\\mathrm{ln}\\left(0.716\\right)[\/latex] using a calculator. Round to the nearest thousandth.\r\n\r\n12.\u00a0Graph the function [latex]g\\left(x\\right)=\\mathrm{log}\\left(12 - 6x\\right)+3[\/latex].\r\n\r\n13. State the domain, vertical asymptote, and end behavior of the function [latex]f\\left(x\\right)={\\mathrm{log}}_{5}\\left(39 - 13x\\right)+7[\/latex].\r\n\r\n14.\u00a0Rewrite [latex]\\mathrm{log}\\left(17a\\cdot 2b\\right)[\/latex] as a sum.\r\n\r\n15. Rewrite [latex]{\\mathrm{log}}_{t}\\left(96\\right)-{\\mathrm{log}}_{t}\\left(8\\right)[\/latex] in compact form.\r\n\r\n16.\u00a0Rewrite [latex]{\\mathrm{log}}_{8}\\left({a}^{\\frac{1}{b}}\\right)[\/latex] as a product.\r\n\r\n17. Use properties of logarithm to expand [latex]\\mathrm{ln}\\left({y}^{3}{z}^{2}\\cdot \\sqrt[3]{x - 4}\\right)[\/latex].\r\n\r\n18.\u00a0Condense the expression [latex]4\\mathrm{ln}\\left(c\\right)+\\mathrm{ln}\\left(d\\right)+\\frac{\\mathrm{ln}\\left(a\\right)}{3}+\\frac{\\mathrm{ln}\\left(b+3\\right)}{3}[\/latex] to a single logarithm.\r\n\r\n19. Rewrite [latex]{16}^{3x - 5}=1000[\/latex] as a logarithm. Then apply the change of base formula to solve for [latex]x[\/latex] using the natural log. Round to the nearest thousandth.\r\n\r\n20.\u00a0Solve [latex]{\\left(\\frac{1}{81}\\right)}^{x}\\cdot \\frac{1}{243}={\\left(\\frac{1}{9}\\right)}^{-3x - 1}[\/latex] by rewriting each side with a common base.\r\n\r\n21. Use logarithms to find the exact solution for [latex]-9{e}^{10a - 8}-5=-41[\/latex] . If there is no solution, write no solution.\r\n\r\n22.\u00a0Find the exact solution for [latex]10{e}^{4x+2}+5=56[\/latex]. If there is no solution, write no solution.\r\n\r\n23. Find the exact solution for [latex]-5{e}^{-4x - 1}-4=64[\/latex]. If there is no solution, write no solution.\r\n\r\n24.\u00a0Find the exact solution for [latex]{2}^{x - 3}={6}^{2x - 1}[\/latex]. If there is no solution, write no solution.\r\n\r\n25. Find the exact solution for [latex]{e}^{2x}-{e}^{x}-72=0[\/latex]. If there is no solution, write no solution.\r\n\r\n26.\u00a0Use the definition of a logarithm to find the exact solution for [latex]4\\mathrm{log}\\left(2n\\right)-7=-11[\/latex]\r\n\r\n27. Use the one-to-one property of logarithms to find an exact solution for [latex]\\mathrm{log}\\left(4{x}^{2}-10\\right)+\\mathrm{log}\\left(3\\right)=\\mathrm{log}\\left(51\\right)[\/latex] If there is no solution, write no solution.\r\n\r\n28.\u00a0The formula for measuring sound intensity in decibels D<\/em>\u00a0is defined by the equation [latex]D=10\\mathrm{log}\\left(\\frac{I}{{I}_{0}}\\right)[\/latex], where I<\/em>\u00a0is the intensity of the sound in watts per square meter and [latex]{I}_{0}={10}^{-12}[\/latex] is the lowest level of sound that the average person can hear. How many decibels are emitted from a rock concert with a sound intensity of [latex]4.7\\cdot {10}^{-1}[\/latex] watts per square meter?\r\n\r\n29. A radiation safety officer is working with 112 grams of a radioactive substance. After 17 days, the sample has decayed to 80 grams. Rounding to five significant digits, write an exponential equation representing this situation. To the nearest day, what is the half-life of this substance?\r\n\r\n30.\u00a0Write the formula found in the previous exercise as an equivalent equation with base [latex]e[\/latex]. Express the exponent to five significant digits.\r\n\r\n31. A bottle of soda with a temperature of 71\u00ba Fahrenheit was taken off a shelf and placed in a refrigerator with an internal temperature of 35\u00ba F. After ten minutes, the internal temperature of the soda was 63\u00ba F. Use Newton\u2019s Law of Cooling to write a formula that models this situation. To the nearest degree, what will the temperature of the soda be after one hour?\r\n\r\n32.\u00a0The population of a wildlife habitat is modeled by the equation [latex]P\\left(t\\right)=\\frac{360}{1+6.2{e}^{-0.35t}}[\/latex], where t<\/em>\u00a0is given in years. How many animals were originally transported to the habitat? How many years will it take before the habitat reaches half its capacity?\r\n\r\n33. Enter the data from the table below into a graphing calculator and graph the resulting scatter plot. Determine whether the data from the table would likely represent a function that is linear, exponential, or logarithmic.\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n
x<\/em><\/strong><\/td>\r\nf(x)<\/em><\/strong><\/td>\r\n<\/tr>\r\n
1<\/td>\r\n3<\/td>\r\n<\/tr>\r\n
2<\/td>\r\n8.55<\/td>\r\n<\/tr>\r\n
3<\/td>\r\n11.79<\/td>\r\n<\/tr>\r\n
4<\/td>\r\n14.09<\/td>\r\n<\/tr>\r\n
5<\/td>\r\n15.88<\/td>\r\n<\/tr>\r\n
6<\/td>\r\n17.33<\/td>\r\n<\/tr>\r\n
7<\/td>\r\n18.57<\/td>\r\n<\/tr>\r\n
8<\/td>\r\n19.64<\/td>\r\n<\/tr>\r\n
9<\/td>\r\n20.58<\/td>\r\n<\/tr>\r\n
10<\/td>\r\n21.42<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n34.\u00a0The population of a lake of fish is modeled by the logistic equation [latex]P\\left(t\\right)=\\frac{16,120}{1+25{e}^{-0.75t}}[\/latex], where t<\/em>\u00a0is time in years. To the nearest hundredth, how many years will it take the lake to reach 80% of its carrying capacity?\r\n\r\nFor the following exercises, use a graphing utility to create a scatter diagram of the data given in the table. Observe the shape of the scatter diagram to determine whether the data is best described by an exponential, logarithmic, or logistic model. Then use the appropriate regression feature to find an equation that models the data. When necessary, round values to five decimal places.\r\n\r\n35.\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n
x<\/em><\/strong><\/td>\r\nf(x)<\/em><\/strong><\/td>\r\n<\/tr>\r\n
1<\/td>\r\n20<\/td>\r\n<\/tr>\r\n
2<\/td>\r\n21.6<\/td>\r\n<\/tr>\r\n
3<\/td>\r\n29.2<\/td>\r\n<\/tr>\r\n
4<\/td>\r\n36.4<\/td>\r\n<\/tr>\r\n
5<\/td>\r\n46.6<\/td>\r\n<\/tr>\r\n
6<\/td>\r\n55.7<\/td>\r\n<\/tr>\r\n
7<\/td>\r\n72.6<\/td>\r\n<\/tr>\r\n
8<\/td>\r\n87.1<\/td>\r\n<\/tr>\r\n
9<\/td>\r\n107.2<\/td>\r\n<\/tr>\r\n
10<\/td>\r\n138.1<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n36.\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n
x<\/em><\/strong><\/td>\r\nf(x)<\/em><\/strong><\/td>\r\n<\/tr>\r\n
3<\/td>\r\n13.98<\/td>\r\n<\/tr>\r\n
4<\/td>\r\n17.84<\/td>\r\n<\/tr>\r\n
5<\/td>\r\n20.01<\/td>\r\n<\/tr>\r\n
6<\/td>\r\n22.7<\/td>\r\n<\/tr>\r\n
7<\/td>\r\n24.1<\/td>\r\n<\/tr>\r\n
8<\/td>\r\n26.15<\/td>\r\n<\/tr>\r\n
9<\/td>\r\n27.37<\/td>\r\n<\/tr>\r\n
10<\/td>\r\n28.38<\/td>\r\n<\/tr>\r\n
11<\/td>\r\n29.97<\/td>\r\n<\/tr>\r\n
12<\/td>\r\n31.07<\/td>\r\n<\/tr>\r\n
13<\/td>\r\n31.43<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n37.\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n
x<\/em><\/strong><\/td>\r\nf(x)<\/em><\/strong><\/td>\r\n<\/tr>\r\n
0<\/td>\r\n2.2<\/td>\r\n<\/tr>\r\n
0.5<\/td>\r\n2.9<\/td>\r\n<\/tr>\r\n
1<\/td>\r\n3.9<\/td>\r\n<\/tr>\r\n
1.5<\/td>\r\n4.8<\/td>\r\n<\/tr>\r\n
2<\/td>\r\n6.4<\/td>\r\n<\/tr>\r\n
3<\/td>\r\n9.3<\/td>\r\n<\/tr>\r\n
4<\/td>\r\n12.3<\/td>\r\n<\/tr>\r\n
5<\/td>\r\n15<\/td>\r\n<\/tr>\r\n
6<\/td>\r\n16.2<\/td>\r\n<\/tr>\r\n
7<\/td>\r\n17.3<\/td>\r\n<\/tr>\r\n
8<\/td>\r\n17.9<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n ","rendered":"

1. The population of a pod of bottlenose dolphins is modeled by the function [latex]A\\left(t\\right)=8{\\left(1.17\\right)}^{t}[\/latex], where t<\/em>\u00a0is given in years. To the nearest whole number, what will the pod population be after 3\u00a0years?<\/p>\n

2.\u00a0Find an exponential equation that passes through the points (0, 4) and (2, 9).<\/p>\n

3. Drew wants to save $2,500 to go to the next World Cup. To the nearest dollar, how much will he need to invest in an account now with 6.25% APR, compounding daily, in order to reach his goal in 4\u00a0years?<\/p>\n

4.\u00a0An investment account was opened with an initial deposit of $9,600 and earns 7.4% interest, compounded continuously. How much will the account be worth after 15 years?<\/p>\n

5. Graph the function [latex]f\\left(x\\right)=5{\\left(0.5\\right)}^{-x}[\/latex] and its reflection across the y<\/em>-axis on the same axes, and give the y<\/em>-intercept.<\/p>\n

6. The graph shows transformations of the graph of [latex]f\\left(x\\right)={\\left(\\frac{1}{2}\\right)}^{x}[\/latex]. What is the equation for the transformation?<\/p>\n

\"Graph<\/p>\n

7.\u00a0Rewrite [latex]{\\mathrm{log}}_{8.5}\\left(614.125\\right)=a[\/latex] as an equivalent exponential equation.<\/p>\n

8.\u00a0Rewrite [latex]{e}^{\\frac{1}{2}}=m[\/latex] as an equivalent logarithmic equation.<\/p>\n

9. Solve for x<\/em>\u00a0by converting the logarithmic equation [latex]log_{\\frac{1}{7}}\\left(x\\right)=2[\/latex] to exponential form.<\/p>\n

10.\u00a0Evaluate [latex]\\mathrm{log}\\left(\\text{10,000,000}\\right)[\/latex] without using a calculator.<\/p>\n

11. Evaluate [latex]\\mathrm{ln}\\left(0.716\\right)[\/latex] using a calculator. Round to the nearest thousandth.<\/p>\n

12.\u00a0Graph the function [latex]g\\left(x\\right)=\\mathrm{log}\\left(12 - 6x\\right)+3[\/latex].<\/p>\n

13. State the domain, vertical asymptote, and end behavior of the function [latex]f\\left(x\\right)={\\mathrm{log}}_{5}\\left(39 - 13x\\right)+7[\/latex].<\/p>\n

14.\u00a0Rewrite [latex]\\mathrm{log}\\left(17a\\cdot 2b\\right)[\/latex] as a sum.<\/p>\n

15. Rewrite [latex]{\\mathrm{log}}_{t}\\left(96\\right)-{\\mathrm{log}}_{t}\\left(8\\right)[\/latex] in compact form.<\/p>\n

16.\u00a0Rewrite [latex]{\\mathrm{log}}_{8}\\left({a}^{\\frac{1}{b}}\\right)[\/latex] as a product.<\/p>\n

17. Use properties of logarithm to expand [latex]\\mathrm{ln}\\left({y}^{3}{z}^{2}\\cdot \\sqrt[3]{x - 4}\\right)[\/latex].<\/p>\n

18.\u00a0Condense the expression [latex]4\\mathrm{ln}\\left(c\\right)+\\mathrm{ln}\\left(d\\right)+\\frac{\\mathrm{ln}\\left(a\\right)}{3}+\\frac{\\mathrm{ln}\\left(b+3\\right)}{3}[\/latex] to a single logarithm.<\/p>\n

19. Rewrite [latex]{16}^{3x - 5}=1000[\/latex] as a logarithm. Then apply the change of base formula to solve for [latex]x[\/latex] using the natural log. Round to the nearest thousandth.<\/p>\n

20.\u00a0Solve [latex]{\\left(\\frac{1}{81}\\right)}^{x}\\cdot \\frac{1}{243}={\\left(\\frac{1}{9}\\right)}^{-3x - 1}[\/latex] by rewriting each side with a common base.<\/p>\n

21. Use logarithms to find the exact solution for [latex]-9{e}^{10a - 8}-5=-41[\/latex] . If there is no solution, write no solution.<\/p>\n

22.\u00a0Find the exact solution for [latex]10{e}^{4x+2}+5=56[\/latex]. If there is no solution, write no solution.<\/p>\n

23. Find the exact solution for [latex]-5{e}^{-4x - 1}-4=64[\/latex]. If there is no solution, write no solution.<\/p>\n

24.\u00a0Find the exact solution for [latex]{2}^{x - 3}={6}^{2x - 1}[\/latex]. If there is no solution, write no solution.<\/p>\n

25. Find the exact solution for [latex]{e}^{2x}-{e}^{x}-72=0[\/latex]. If there is no solution, write no solution.<\/p>\n

26.\u00a0Use the definition of a logarithm to find the exact solution for [latex]4\\mathrm{log}\\left(2n\\right)-7=-11[\/latex]<\/p>\n

27. Use the one-to-one property of logarithms to find an exact solution for [latex]\\mathrm{log}\\left(4{x}^{2}-10\\right)+\\mathrm{log}\\left(3\\right)=\\mathrm{log}\\left(51\\right)[\/latex] If there is no solution, write no solution.<\/p>\n

28.\u00a0The formula for measuring sound intensity in decibels D<\/em>\u00a0is defined by the equation [latex]D=10\\mathrm{log}\\left(\\frac{I}{{I}_{0}}\\right)[\/latex], where I<\/em>\u00a0is the intensity of the sound in watts per square meter and [latex]{I}_{0}={10}^{-12}[\/latex] is the lowest level of sound that the average person can hear. How many decibels are emitted from a rock concert with a sound intensity of [latex]4.7\\cdot {10}^{-1}[\/latex] watts per square meter?<\/p>\n

29. A radiation safety officer is working with 112 grams of a radioactive substance. After 17 days, the sample has decayed to 80 grams. Rounding to five significant digits, write an exponential equation representing this situation. To the nearest day, what is the half-life of this substance?<\/p>\n

30.\u00a0Write the formula found in the previous exercise as an equivalent equation with base [latex]e[\/latex]. Express the exponent to five significant digits.<\/p>\n

31. A bottle of soda with a temperature of 71\u00ba Fahrenheit was taken off a shelf and placed in a refrigerator with an internal temperature of 35\u00ba F. After ten minutes, the internal temperature of the soda was 63\u00ba F. Use Newton\u2019s Law of Cooling to write a formula that models this situation. To the nearest degree, what will the temperature of the soda be after one hour?<\/p>\n

32.\u00a0The population of a wildlife habitat is modeled by the equation [latex]P\\left(t\\right)=\\frac{360}{1+6.2{e}^{-0.35t}}[\/latex], where t<\/em>\u00a0is given in years. How many animals were originally transported to the habitat? How many years will it take before the habitat reaches half its capacity?<\/p>\n

33. Enter the data from the table below into a graphing calculator and graph the resulting scatter plot. Determine whether the data from the table would likely represent a function that is linear, exponential, or logarithmic.<\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n
x<\/em><\/strong><\/td>\nf(x)<\/em><\/strong><\/td>\n<\/tr>\n
1<\/td>\n3<\/td>\n<\/tr>\n
2<\/td>\n8.55<\/td>\n<\/tr>\n
3<\/td>\n11.79<\/td>\n<\/tr>\n
4<\/td>\n14.09<\/td>\n<\/tr>\n
5<\/td>\n15.88<\/td>\n<\/tr>\n
6<\/td>\n17.33<\/td>\n<\/tr>\n
7<\/td>\n18.57<\/td>\n<\/tr>\n
8<\/td>\n19.64<\/td>\n<\/tr>\n
9<\/td>\n20.58<\/td>\n<\/tr>\n
10<\/td>\n21.42<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

34.\u00a0The population of a lake of fish is modeled by the logistic equation [latex]P\\left(t\\right)=\\frac{16,120}{1+25{e}^{-0.75t}}[\/latex], where t<\/em>\u00a0is time in years. To the nearest hundredth, how many years will it take the lake to reach 80% of its carrying capacity?<\/p>\n

For the following exercises, use a graphing utility to create a scatter diagram of the data given in the table. Observe the shape of the scatter diagram to determine whether the data is best described by an exponential, logarithmic, or logistic model. Then use the appropriate regression feature to find an equation that models the data. When necessary, round values to five decimal places.<\/p>\n

35.<\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n
x<\/em><\/strong><\/td>\nf(x)<\/em><\/strong><\/td>\n<\/tr>\n
1<\/td>\n20<\/td>\n<\/tr>\n
2<\/td>\n21.6<\/td>\n<\/tr>\n
3<\/td>\n29.2<\/td>\n<\/tr>\n
4<\/td>\n36.4<\/td>\n<\/tr>\n
5<\/td>\n46.6<\/td>\n<\/tr>\n
6<\/td>\n55.7<\/td>\n<\/tr>\n
7<\/td>\n72.6<\/td>\n<\/tr>\n
8<\/td>\n87.1<\/td>\n<\/tr>\n
9<\/td>\n107.2<\/td>\n<\/tr>\n
10<\/td>\n138.1<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

36.<\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
x<\/em><\/strong><\/td>\nf(x)<\/em><\/strong><\/td>\n<\/tr>\n
3<\/td>\n13.98<\/td>\n<\/tr>\n
4<\/td>\n17.84<\/td>\n<\/tr>\n
5<\/td>\n20.01<\/td>\n<\/tr>\n
6<\/td>\n22.7<\/td>\n<\/tr>\n
7<\/td>\n24.1<\/td>\n<\/tr>\n
8<\/td>\n26.15<\/td>\n<\/tr>\n
9<\/td>\n27.37<\/td>\n<\/tr>\n
10<\/td>\n28.38<\/td>\n<\/tr>\n
11<\/td>\n29.97<\/td>\n<\/tr>\n
12<\/td>\n31.07<\/td>\n<\/tr>\n
13<\/td>\n31.43<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

37.<\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
x<\/em><\/strong><\/td>\nf(x)<\/em><\/strong><\/td>\n<\/tr>\n
0<\/td>\n2.2<\/td>\n<\/tr>\n
0.5<\/td>\n2.9<\/td>\n<\/tr>\n
1<\/td>\n3.9<\/td>\n<\/tr>\n
1.5<\/td>\n4.8<\/td>\n<\/tr>\n
2<\/td>\n6.4<\/td>\n<\/tr>\n
3<\/td>\n9.3<\/td>\n<\/tr>\n
4<\/td>\n12.3<\/td>\n<\/tr>\n
5<\/td>\n15<\/td>\n<\/tr>\n
6<\/td>\n16.2<\/td>\n<\/tr>\n
7<\/td>\n17.3<\/td>\n<\/tr>\n
8<\/td>\n17.9<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

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