Problem 5.3 null function

[yhkalayci]

Can we use null function ?

[mehmetburakkurutmaz]

It is trivial in 2x2 case, but since it is trivial you can use null.

To imitate hand calculation in 2x2:
If matrix A has a null space having dimension 1 (if 2, then A=0), then null space consists of the line that is passing through the origin and perpendicular to first row (or alternatively the second).