Question

F(x)= sqrt x-5
Find f-1

Answer 1

The answer is the first option,
`f\textsuperscript{-1}(x)=x^2+5; y \geq 5.`

When finding the inverse of a function, first replace
`f(x)` with
`y`, and interchange the variables.


`f(x)= √(x-5) \\ y= √(x-5) \\ x= √(y-5)`

Then, solve the equation for y. This will give you the inverse function.

`x= √(y-5) \\ x^2 = y-5 \\ y = x^2+5 \\ f\textsuperscript{-1}(x)=x^2+5`