y intercepts of polynomials

Question

The polynomial of degree 3, P(x), has a root of multiplicity 2 at x=2 and a root of multiplicity 1 at x=−1. The y-intercept is y=−2.8;
Find a formula for P(x).

 

The polynomial is (x-2)^2(x+1) but i'm not sure what to do with the y intercept portion.

Answer 1

f(x) = a(x - 2)²(x + 1)

f(x) = a(x² - 4x + 4)(x + 1)

f(x) = a(x³ - 3x² + 4)

y-intercept, -2.8, occurs at x = 0

-2.8 = a(4)

-0.7 = a

f(x) = -0.7(x³ - 3x² + 4)