How do you find (g o f)(x) given f(x)=xx2, g(x)=3x?

1 Answer
Dec 19, 2015

(gf)(x)=3x6x

Explanation:

(gf)(x) just means that g is a function of f(x), so we need to replace x in g(x) with f(x).

g(x)=3x

Replace each x with f(x). In this case, there is only one.

(gf)(x)=3f(x)

Now plug in the value of f(x).

(gf)(x)=3xx2

Simplify.

(gf)(x)=3(x2)x

(gf)(x)=3x6x