Question

For f (x) = 4x +1 and g(x) = x2 - 5, find (f.g)(x).

Answer 1

4x³ + x² - 20x - 5

Explanation:

Calculate f(x) × g(x), that is

(4x + 1)(x² - 5)

Each term in the second factor is multiplied by each term in the first factor, that is

4x(x² - 5) + 1(x² - 5) ← distribute both parenthesis

= 4x³ - 20x + x² - 5

= 4x³ + x² - 20x - 5 ← in standard form