Answer:
C. f^-1(x) = 1/5x
Step-by-step explanation:
You know that f^-1(f(x)) = x, so you can try the answers.
- A: f^-1(5x) = -25x . . . . not it
- B: f^-1(5x) = -x . . . . . . not it
- C: f^-1(5x) = x . . . . . . . correct choice
- D: f^-1(5x) = 25x . . . . not it
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You can also solve for f^-1(x). It will be "y" when ...
f(y) = x
5y = x
y = 1/5x . . . . . divide by 5
