If f (x) = x + 2 and g (x) = 3x + 4, then (g °f) (x) = ?

a. 3x + 6

b. 3x + 10

c. 3x^2 + 6x + 4

d. 3x^2 + 10x + 6

The correct answer is a. 3x + 6

In order to find a compound function, you must use the first letter in the function (in this case f) and plug the second letter (g) in where you see x's.

f (x) = x + 2

f (g (x)) = (g (x)) + 2

f (g (x)) = (3x + 4) + 2

f (g (x)) = 3x + 6