2. (a) Let A be an m x n matrix of rank n and let b ERM. Solve the problem Minimize || Ax b|| , where ||y|| = (Oh y?) for any y = (41, 42, ... , Ym)? E RM. (b) Let (21,41), (02, y2), ..., (In, yn) be n points in the xy-plane such that xi's are not all equal. Find constants a and b that minimize = (a + bxi yi)2