The polynomial of degree 3, P(x), has a root of multiplicity 2 at x=2 and a root of multiplicity 1 at x=-2. The y-intercept is y= -4.8 . Find a formula for P(x) .
Please check my answer!
P(x)=(x-2)^2(x+2)-4.8 is that right?

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=-2. The y-intercept is y= -4.8 . Find a formula for P(x) . 
Please check my answer! 
P(x)=(x-2)^2(x+2)-4.8 is that right?

campbell_st · Answer

nope not quite right

 $$P(x) = k( x+2)(x-2)^2$$

then 

$$P(x) = k(x +2)(x^2 -4x + 4)$$

so the constant term after distributing is 8

so you know that 

4.8 = 8k

solve for k

then you can fully distribute to find the equation of the polynomial.,

Hope this helps.

anonymous · Answer

x^3-2x^2-4x-8  is 8 from this ? right?