# Thread: Solving the Function composition

1. ## Solving the Function composition

Given :

$f(h(x)) = \sqrt{(x^2+9)}$

and

$h(x) = x^2 + 9$

find : $h(f(x))$

2. Clearly, $f(x)=\sqrt{x}$.

I think you can complete it.

3. I'm a bit confused as to what the difficulty is. If you are told that
$f(h(x))= \sqrt{(x^2+ 9)}$ and that $h(x)= x^2+ 9$ then it should be obvious that $f(x)= \sqrt{x}$. From that, $h(f(x))= (\sqrt{x})^2+ 9= x+ 9$.

4. This is not a tricky problem. Please give some thought to why you are struggling with it. It requires ONLY an understanding of function notation.

$f(x)\;=\;\sqrt{x}$

You WILL want to worry about the Domain a little.

5. O.o

I didn't know this is that easy =.= I was thinking of something more complex

Thx u all