Let f(x) be a quadratic polynomial such that f(-4) = -22, f(-1)=2 , and f(2)=-1. Let g(x) = f(x)^{16}. Find the sum of the coefficients of the terms in g(x) that have even degree. (For example, the sum of the coefficients of the terms in -7x^3 + 4x^2 + 10x - 5 that have even degree is (4) + (-5) = -1.)
My findings : f(x) = -3/2x^2 + 1/2x + 4.
You have the correct f(x).
To find the sum of the even coefficients of f(x)^16 simply calculate (f(1)^16 + f(-1)^16)/2.