Question

Let f(x)=5x-7 and g(x)=(x+4)^2. Find the composite function f(g(x))

Answer 1

Do you have to simplify it, or can you leave it un-simplified?

Answer 2

I think it has to be simplified

Answer 3

Okay, start by simplifying g(x).

Answer 4

\(\Large (x+4)^2=(x+4)(x+4)\) FOIL it.

Answer 5

ok thanks

Answer 6

is that all I have to do?

Answer 7

But after that, you have to plug whatever you get for \(g(x)\) into \(f(x)\), and distribute that.

Answer 8

So \(g(x)=x^2+8x+16\) would get plugged in:

\(\Large f(g(x))=5(x^2+8x+16)-7\)
Now you have to simplify that, and that will be your simplified composite function.

Answer 9

Oh, alternative form is \(\Large f(g(x))=5((x+4)^2)-7\)

Answer 10

Both are right, just depends on which one you want.

Answer 11

ohh ok so I just simplify that and I get the answer?

Answer 12

That is correct.

Answer 13

ok thank you!

Answer 14

Anytime :)