True of False? Give reasons why
6 If A is an invertible matrir, then there are no least square solutions for Arb The matriz AT A is a symmetric matriz. 8 Let Q [q1 . . . ln be a square matrix uth orthogonal columns. Then an Q-1 9 If Xi, x2 are least-squares solutions to Ax = b, then Xi +x2 is a least-squares solution 10 If x1,x2 are least-squares solutions to Ax -0, then x x2 is a least-squares solution 11 Ifx is least-squares solutions to Ax-b and y in Nul(A), then x+y is a least-squares toAx = b. to Ax 0 solution to Ax b