Question

Use the functions f(x) = 4x² + 3 and g(x) = 3x + 2 to evaluate the following.

g(f(-2)) =
f(g(-2)) =

Answer 1

1. 58
2. 67

Explanation:

f(x) = 4x² + 3

g(x) = 3x + 2

1. g (f(-2)) =

f(-2) = 4(-2)² + 3

= 4(4) + 3 = 19

g(f(-2)) = g(19) = 3(19) + 1 = 57 + 1 = 58

2. f(g(-2)) =

g(-2) = 3(-2) + 2

= -6 + 2 = -4

f(g(-2)) = f(-4) = 4 (-4)² + 3 = 4(16) + 3 = 64 + 3 = 67

Answer 2

Explanation:

f(-2)= 4(-2)^2 + 3 = 4(4) + 3 = 16 + 3 = 19

g(19) = 3(19) + 2 = 57 + 2 = 59

g(-2)= 3(-2) + 2 = -6 + 2 = -4

f(-4)= 4(-4)^2 + 3 = 64 + 3 = 67