Question

.Find (g o f)(x) for f(x) = 2x + 4 and g(x) = x^2 . Show all of your work, it'll help me for my next one ! (: thanks

Answer 1

You should know that (g o f)(x) is the same as g(f(x)), or g of f(x). To solve for g(f(x)), substitute whatever f(x) equals as x into g(x).

So, if you have the two functions
g(x) = x^2
f(x) = 2x + 4, 
you substitute what f(x) equals as x into the g(x) equation.
$g(x) = x^2 \\ g(f(x)) = (f(x))^2 \\ g(f(x)) = (2x + 4)^2 \\ g(f(x)) = 4x^2 + 16x + 16$