i stumbled upon a problem in my homework and i think i did something wrong. I tried to get a residuum using first the QR factorization method (using Givensrotations) and then the Normal equation Method and i got a smaller residuum with the Normal equation method. Is this what am i supposed to get or calculating the residuum with the QR Factorization method( using Givensrotation ) is supposed to give a smaller residuum?
The Matrices given in the problem were A =[1 1;0 1;0 2;0 3] and b = [1;1;1;1] using the QR method i got a residuum of 1,2186 and using the normal equation method i got a residuum of 0,6547.
Thanks in advance for the help.