Question

If f(x) = 5x, what is f–1(x)?

Answer 1

it would be 1/5x so C

Answer 2

Correct option is:

`f^(-1)(x)=(x)/(5)`

Explanation:

Let f(x)=y

Then,
`f^(-1)(y)=x`

Hence, Value of x in terms of y gives the value of
`f^(-1)(x)`

f(x)=y

i.e. 5x=y

i.e. x=y/5

Hence,
`f^(-1)(y)=(y)/(5)`

Replacing y by x, we get

`f^(-1)(x)=(x)/(5)`

Hence, correct option is:

`f^(-1)(x)=(x)/(5)`