• Sep 1st 2008, 04:52 PM
OnMyWayToBeAMathProffesor
I have total forgotten how to do these, f(x)=4x , h(x)=x+5
what is (f+h)(x)? Thank you everybody.
• Sep 1st 2008, 05:01 PM
Chop Suey
$(f+h)(x) = f(x) + h(x)$
• Sep 1st 2008, 07:09 PM
OnMyWayToBeAMathProffesor
I knew it was something simple like that, thank you very much for unlocking all of my past knowledge but I still can not remember what these kind of problems of called, are they conjunctions?
• Sep 1st 2008, 07:21 PM
OnMyWayToBeAMathProffesor
I am sorry, but another quick question, $f(x)=4x$ , $h(x)=x+5$ , $g(x)=x^2$

then $f(g(h(x)))$ = $16x^2+5$ or $4(x+5)^2=4x^2+40X+100$
• Sep 1st 2008, 07:26 PM
11rdc11
Nope try again.

Should be,

$4x^2 + 40x +100$
• Sep 1st 2008, 07:29 PM
OnMyWayToBeAMathProffesor
Thank you, I saw my error and edited my last post, I made a very foolish mistake. the answer is actually $4(x+5)^2=4x^2+40X+100$ like you said. Thanks again.
• Sep 1st 2008, 07:31 PM
11rdc11
No problem glad to help anytime.