Question

If f(x) = 5x, what is f–1(x)?

Answer 1

Please, take just a little more time and write the label "inverse function" like this:

-1

f (x). We want the inverse function of f(x) = 5x.

How to obtain it:

1) replace f(x) by y.

2) interchange x and y: x = 5y

3) solve this result for y: y = x/5

4) replace y with the correct symbol for "inverse function of f:"

-1

f (x) = x/5 (answer)

Answer 2

`f(x)=5x\to y=5x`

change x to y, and y to x

`x=5y`

solve for y:

`5y=x\ \ \ |:5\\\\y=(x)/(5)\to y=(1)/(5)x`

Answer:

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