PS 6

3.1.5

>> X = [1 1; 1.5 1; 2 1; 2.5 1; 3 1]

X =

    1.0000    1.0000
    1.5000    1.0000
    2.0000    1.0000
    2.5000    1.0000
    3.0000    1.0000

>> Y = [1.1; 1.2; 1.3; 1.3; 1.4]

Y =

    1.1000
    1.2000
    1.3000
    1.3000
    1.4000

>> X \ Y

ans =

    0.1400
    0.9800

>> x = 1:.5:3;
>> y = [1.1 1.2 1.3 1.3 1.4];

>> yline=.14*x + .98;
>> plot(x,y,'.',x,yline)

>> s = X \ Y

s =

    0.1400
    0.9800

>> norm(X*s - Y,2)

ans =

0.0548