Solutions

Solutions to Try Its

1. h(2)=6

2. Yes

3. Yes

4. The domain of function f1 is (,2) and the range of function f1 is (1,).

5. a. f(60)=50. In 60 minutes, 50 miles are traveled.

b. f1(60)=70. To travel 60 miles, it will take 70 minutes.

6. a. 3; b. 5.6

7. x=3y+5

8. f1(x)=(2x)2;domainoff:[0,);domainoff1:(,2]

9.
Graph of f(x) and f^(-1)(x).

Solutions to Odd-Numbered Exercises

1. Each output of a function must have exactly one output for the function to be one-to-one. If any horizontal line crosses the graph of a function more than once, that means that y -values repeat and the function is not one-to-one. If no horizontal line crosses the graph of the function more than once, then no y -values repeat and the function is one-to-one.

3. Yes. For example, f(x)=1x is its own inverse.

5. Given a function y=f(x), solve for x in terms of y. Interchange the x and y. Solve the new equation for y. The expression for y is the inverse, y=f1(x).

7. f1(x)=x3

9. f1(x)=2x

11. f1(x)=2xx1

13. domain of f(x):[7,);f1(x)=x7

15. domain of f(x):[0,);f1(x)=x+5

17. f(g(x))=x,g(f(x))=x

19. one-to-one

21. one-to-one

23. not one-to-one

25. 3

27. 2

29.
Graph of a square root function and its inverse.

31. [2,10]

33. 6

35. 4

37. 0

39. 1

41.

x 1 4 7 12 16
f1(x) 3 6 9 13 14

43. f1(x)=(1+x)1/3
Graph of a cubic function and its inverse.

45. f1(x)=59(x32). Given the Fahrenheit temperature, x, this formula allows you to calculate the Celsius temperature.

47. t(d)=d50, t(180)=18050. The time for the car to travel 180 miles is 3.6 hours.