A third degree polynomial has a real root at 4, a double real root at -1 and passes the point (-6,12). How can I find the equation for the function? I forgot how to do this, please explain!

Question

campbell_st · Answer

ok... so use the zeros 1st to find the linear factors... can you do that

anonymous · Answer

(x-4) and (x+1). then use foil?

campbell_st · Answer

well close... you have a double zero so 

$$P(x) = a(x -4)(x + 1)^2$$

now substitute the point to find a, then you can expand to get the equation.

anonymous · Answer

oh, okay thank you.