Question

Let f(x) =3x, g(x)=x+1. Find the composite function. (F•g)(2)

Answer 1

Same thing as other question you had.

This time it's f(g(x))

So first you find g(2) = 2 + 1 = 3
Then plug that inside f(x):
f(3) = 3*3 = (?) <-- Solve that part

Answer 2

wouldnt it just be:
(3x*x+1)(2)
???

Answer 3

@turbostudier
No, it would not

and for mhchen
It is not quite right!

The correct procedure is to replace every x in f(x) with all of g(x)
That means:
\[f(g(x))=3.g(x)=3(x+1)=3x+3\]
then substitute with 2
\[f(g(x))=3(2)+3=6+3=9\]