I'm a bit confused, conceptually. This is the problem
Let v1=( 1, -1, 2) v2=( 2, 1, 3) v3=( 1, -4, 3)
Find a nonzero vector u that is orthogonal to all three vectors v1, v2, and v3. I know how to find the projection matrix, P, which I can solve with v1, v2, and v3.
The equation for that is...