Question

If f(x) = x2 + 7, what is the equation for f–1(x)?
Grad point B.S. first to answer gets a medal.

Answer 1

to find inverse:
let y=f(x)
so\[y=x^{2}+7\]
now find x from above.
\[x ^{2}=y-7\]
\[x=\pm\sqrt{y-7}\]
now exchange x and y
\[y= \pm \sqrt{x-7}\]
so inverse of \[f ^{-1}(x)=\pm \sqrt{x-7}\]

Answer 2

Thanks man, that really helped.

Answer 3

you're welcome..:)