Question

How do you find the inverse of `f(x) = x^2 + 9`?

Answer 1

`color(white)xxf^-1(x)=sqrt(x-9)`

Explanation:

`color(white)xxf(x)=x^2+9`

`color(white)xxy=x^2+9`
`=>ycolor(red)(-9)=x^2+9color(red)(-9)`
`=>sqrt(x^2)=sqrt(y-9)`

`=>f^-1(x)=sqrt(x-9)`