# Thread: Composition of a function

1. ## Composition of a function

(f o g)(-2)

f(x) = x^2 - 2x
g(x) = 3x + 2

Do I have to plug in (-2) in g, and then plug that number into f?
Or do i have to plug in (-2) to both functions and then plug in what I got for g into f? im confused

2. Originally Posted by NeedHelp18
(f o g)(-2)

f(x) = x^2 - 2x
g(x) = 3x + 2

Do I have to plug in (-2) in g, and then plug that number into f?
That's the correct one

Basically, $(f \circ g)(x)=f(g(x))$