Graphs of Polynomial Functions

Question

The polynomial of degree 3, P(x)has a root of multiplicity 2 at x=4and a root of multiplicity 11at x=−1. The y-intercept is  y=−4.8.

Find a formula for P(x).

P(x)=

Answer 1

a(x-4)^2(x+1)= a(x^2-8x+16)(x+1) = a(x^3 -7x^2 +8x +16)

16a = -4.8

a = -4.8/16 = -0.3

the polynomial of degree 3, with y intercept =-4.8 with root 4 multiplicity 2 and root -1 multiplicity 1

is: f(x) = -0.3x^3 + 2.1x^2 - 2.4x - 4.8