Find the inverse of each function

1. f(x) = 4/(x+2) - 2

2. f(x)= -2x^5 - 3

We are given the following function:

f(x) = 4/(x+2) - 2

We are asked to determine the inverse of this function. To do that we will first change the "f(x)" for "y":

Now we will switch "x" and "y", like this:

Now we will solve for "y", first by adding 2 to both sides:

Now we multiply both sides by "y+2":

Now we divide both sides by "x+2":

Now we subtract 2 to both sides:

Now we change "y" for the inverse of f(x), that is:

And thus we found the inverse. A similar procedure can be used for function 2.

9514 1404 393

  1. f^-1(x) = 4/(x+2) -2

  2. f^-1(x) = (-(x+3)/2)^(1/5)

Step-by-step explanation:

1. As with all "inverse function" problems, solve for y:

  x = f(y)

  x +2 = 4/(y +2) . . . . add 2

  y +2 = 4/(x +2) . . . . . multiply by (y+2)/(x+2)

  y = 4/(x+2) -2 . . . . . subtract 2

We see that this function is its own inverse. The attached graph shows it is symmetrical about the line y=x.

  f^-1(x) = 4/(x+2) -2

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2. x = f(y)

  x +3 = -2y^5 . . . . add 3

  -(x +3)/2 = y^5 . . . . . divide by 2

  (-(x +3)/2)^(1/5) = y . . . . take the 5th root

  f^-1(x) = (-(x +3)/2)^(1/5)

In typeset form, that is ...

This last version is with the denominator "rationalized" and the contents of the radical "simplified." It may be a preferred form.

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The graphs show the function and inverse are symmetrical about the line y=x, as they should be.

1. 3.4/4

2. 0.8/7

3. 0.5 x 3

4. 0.9 x 6

5. 10.8

6. 2.35

7. 0.567

8. 9.35

9. 0.02

10. 0.06

11. 0.16

12. 0.42

13. 0.63

14. 5.6

15. 8.1

16. 9.9

17. 0.28

18. 0.48

19. 0.27

20. 0.49

21. 0.45

22. 0.72

23. 0.9

24. 0.88

25. 0.75

26. 0.16

27. 0.328

28. 0.495

29. 0.72

30. 1.068

a. 12.5 kg

step-by-step explanation:

f = ma

so

m = f/a = (2500 n)/(200 m/s²) = 12.5 kg

1 n = 1 kg·m/s²