A polynomial function f with real coefficients has zeros of 2, -4, and 1. The polynomial also contains the point f(-1) = 6. Write the function in both factored form and polynomial form.

Answer 1

with zeros of 2, -4, and 1, we know we have

y = a(x-2)(x+4)(x-1)
but (-1,6) lies on it, so
6 = a(-3)(3)(-2)
a = 6/18 = 1/3

y = (1/3)(x-2)(x+4)(x-1)

Your turn to express in expanded form,
don't know why anybody would want it.