Question

If f(x) = 3x +1 and g(x) = x2 – 1, find (fog)(2).

Answer 1

f(x) = 3x + 1 g(x) = x^2 - 1 (f°g)(2)

(f°g)(x) = 3(x^2 - 1) + 1

Simplification

(f°g)(x) = 3x^2 - 3 + 1

(f°g)(x) = 3x^2 - 2

Substitute 2

(f°g)(2) = 3(2)^2 - 2

(f°g)(2) = 3(4) - 2

(f°g)(2) = 12 - 2

(f°g)(2) = 10