find an equation for P(x)

Question

The polynomial P(x) has

• degree 3

• a root of multiplicity 2 at x=1

• a root of multiplicity 1 at x = -5

• y-intercept (0, -2.5)

P(x)=

Answer 1

a(x-1)^2(x+5

=a (x^2-2x+1)(x+5)

=a(x^3 +3x^2 -9x +5

a=-.5

= -x^3/2 - 3x^2/2 +9x/2 - 5/2