Question

Write the cubic polynomial function f(x) in expanded form with zeros -5, -3, and 2, given that f(0) = -60.

Answer 1

Hi there!

$y = 2(x + 5)(x + 3)(x - 2)$

Since we are given the zeros, we can derive the basic equation in expanded form:

x = -5

(x + 5)

x = -3

(x + 3)

x = 2

(x - 2)

y = (x + 5)(x + 3)(x - 2)

Multiplying the numbers, however, only gets -30. The y-intercept is -60, so we need a coefficent of 2 in the equation:

y = 2(x + 5)(x + 3)(x - 2)