3. Let {(x;, y;)} are given, x; ( R" and y; E R. Assume N f(aix-b;) + Allal (3) i=1 with f : R -> R is a differentiable function. (a) Compute VF(x). (b) Compute V2F(x). (c) Prove the minimizer of F must be in the form of a* = ).ca;, with c = [C1, C2, ..., CN]T. (d) Re-express the minimization problem (3) in terms of c with fewer unknowns