Question

5) Is 3 a zero (or root) of f(x) = x3 - 9x2 + 11x + 21?

Answer 1

Yes

Explanation:

f(x) = x³ − 9x² + 11x + 21

f(3) = (3)³ − 9(3)² + 11(3) + 21

f(3) = 27 − 81 + 33 + 21

f(3) = 0