SOLUTION: Let f(x) = x^2 - 4 and g(x) = -3x^2. Find g(f(x))... This is a multiply choice question on an assignment. At first, I got the answer -3x^4 - 48 But the answer key said it wa

Algebra ->  Functions -> SOLUTION: Let f(x) = x^2 - 4 and g(x) = -3x^2. Find g(f(x))... This is a multiply choice question on an assignment. At first, I got the answer -3x^4 - 48 But the answer key said it wa      Log On


   

Question 462960: Let f(x) = x^2 - 4 and g(x) = -3x^2. Find g(f(x))...
This is a multiply choice question on an assignment.
At first, I got the answer -3x^4 - 48
But the answer key said it was -3x^4 + 24x^2 - 48
I have no idea how 24x^2 got in there. Can you solve this?
Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
the "g" function is defined as "square and multiply by -3"

so using the "g" function on the "f" function gives ___ -3(x^2 - 4)^2

use FOIL on (x^2 - 4)^2 to get the "middle" term, then multiply by -3