Question

Let f(x) = x2 + x + 2 and g(x) = 2x2 + 5. Find f(g(x)). Show each step of your work.

I just need some help to start. Will fan and medal...

Answer 1

You are plugging in g(x) into f(x).

So you are treating the function g(x) like another x almost.

So where ever you see an "x" in f(x) you plug in the function g(x)

Answer 2

@Luigi0210
So then I start with
f(2x2+5) = (2x2+5) 2 + (2x2+5) + 2?

Answer 3

Yes :)

Answer 4

Now just simplify it and you're done.

Answer 5

This might be a dumb question, but where do I start to simplify it?

Answer 6

"The only dumb questions are the ones you do not ask"

And you can start by dealing with that square term:

\(\large \color{red}{(2x^2+5)^2} +(2x^2+5)+2\)

Should be easier after that (:

Answer 7

Thank you for all your help!

Answer 8

No problem! \(\Large \color{green}{\ddot \smile} \)