Question

Let ƒ(x) = x^2 + 2x and g(x) = 2x. Evaluate the composition (ƒ ∘ g)(2).

Answer 1

The answer is option D.

Explanation:

f(x) = x² + 2x

g(x) = 2x

To find (ƒ ∘ g)(2) first find (ƒ ∘ g)

To find (ƒ ∘ g) wherever you see x in f(x) replace it with g(x)

That's

(ƒ ∘ g) = (2x)² + 2(2x)

= 4x² + 4x

Substitute 2 into the expression

That's

(ƒ ∘ g)(2) = 4(2)² + 4(2)

= 4(4) + 8

= 16 + 8

= 24

Hope this helps you.