Question

Zero of 2 and zero of 4 having multiplicity 2; f(1) = -18

Answer 1

Find a polynomial function

Answer 2

If 2 is a zero, then (x - 2) is a factor.
If 4 is a zero with multiplicity 2, then (x - 4)^2 is a factor.

The polynomial is: f(x) = a * (x-2) * (x-4)^2 where a is a constant.
f(1) = -18. Set x = 1.
f(1) = a * (1-2) * (1-4)^2 = -18
a * (-1) * (9) = -18
-9a = -18
a = 2

f(x) = 2(x-2)(x-4)^2