Solutions to Try Its
1. |x−2|≤3|x−2|≤3
2. using the variable pp for passing, |p−80|≤20|p−80|≤20
3. f(x)=−|x+2|+3f(x)=−|x+2|+3
4. x=−1x=−1 or x=2x=2
5. f(0)=1f(0)=1, so the graph intersects the vertical axis at (0,1)(0,1). f(x)=0f(x)=0 when x=−5x=−5 and x=1x=1 so the graph intersects the horizontal axis at (−5,0)(−5,0) and (1,0)(1,0).
6. 4≤x≤84≤x≤8
7. k≤1k≤1 or k≥7k≥7; in interval notation, this would be (−∞,1]∪[7,∞)(−∞,1]∪[7,∞)
Solutions to Odd-Numbered Exercises
1. Isolate the absolute value term so that the equation is of the form |A|=B|A|=B. Form one equation by setting the expression inside the absolute value symbol, AA, equal to the expression on the other side of the equation, BB. Form a second equation by setting AA equal to the opposite of the expression on the other side of the equation, -B. Solve each equation for the variable.
3. The graph of the absolute value function does not cross the xx -axis, so the graph is either completely above or completely below the xx -axis.
5. First determine the boundary points by finding the solution(s) of the equation. Use the boundary points to form possible solution intervals. Choose a test value in each interval to determine which values satisfy the inequality.
7. |x+4|=12|x+4|=12
9. |f(x)−8|<0.03|f(x)−8|<0.03
11. {1,11}{1,11}
13. {94,134}{94,134}
15. {103,203}{103,203}
17. {115,295}{115,295}
19. {52,72}{52,72}
21. No solution
23. {−57,27}{−57,27}
25. (0,−8);(−6,0),(4,0)(0,−8);(−6,0),(4,0)
27. (0,−7)(0,−7); no xx -intercepts
29. (−∞,−8)∪(12,∞)(−∞,−8)∪(12,∞)
31. −43≤x≤4−43≤x≤4
33. (−∞,−83]∪[6,∞)(−∞,−83]∪[6,∞)
35. (−∞,−83]∪[16,∞)(−∞,−83]∪[16,∞)
37.
39.
41.
43.
45.
47.
49.
51.
53. range: [0,20][0,20]
55. x-x- intercepts:
57. (−∞,∞)(−∞,∞)
59. There is no solution for aa that will keep the function from having a yy -intercept. The absolute value function always crosses the yy -intercept when x=0x=0.
61. |p−0.08|≤0.015|p−0.08|≤0.015
63. |x−5.0|≤0.01|x−5.0|≤0.01
Candela Citations
- Precalculus. Authored by: Jay Abramson, et al.. Provided by: OpenStax. Located at: http://cnx.org/contents/fd53eae1-fa23-47c7-bb1b-972349835c3c@5.175. License: CC BY: Attribution. License Terms: Download For Free at : http://cnx.org/contents/fd53eae1-fa23-47c7-bb1b-972349835c3c@5.175.