function []=hw5_2_9()

% solve an over determined system using pinv, qr and \

A=[2,-3,2; 1.9,-3,2.2; 2.1,-2.9,2; 6.1,2.1,-3; -3,5,2.1];
b=[1.01;1.01;.98;4.94;4.1];

disp('using pinv')
x1=pinv(A)*b

disp('using qr')
[Q,R]=qr(A);
y=Q'*b;
x2=R(1:3,:)\y(1:3)

disp('using \')
x3=A\b