How do you find the polynomial function with roots 1, –2, and 5?

1 Answer

There is more than one polynomial function with roots 11,-22 and 55, but if those are the only roots, and none of them is root more than once, the function is:
p(x) = (x-1) * (x-(-2)) * (x-5) = p(x)=(x1)(x(2))(x5)=
=x^3 - 4*x^2 - 7*x + 10=x34x27x+10

If you ever want to find a polynomial that has x_1x1,x_2x2,...,x_nxn as roots:
p(x) = (x-x_1) * (x-x_2) * ... * (x-x_n)

Hope it helps