5.2.8. Suppose K1 and K2 are positive definite n × n matrices. Suppose that, for i = 1, 2, the minimizer of pi (x) = xTKix − 2xT fi + ci , is x i . Is the minimizer of p(x) = p1 (x) + p2 (x) given by x = x 1 + x 2 ? Prove or give a counterexample.