Q. S is a subspace of R^3 containing only the zero vector. If S is spanned by (1,1,1) and (1,1,-1) what is a basis for S perp?
This is what I have so far -> a+b+c = 0 and a+b-c = 0. 2a+2b = 0
[-b] [-a] 
so a basis is [-1] [-1] 
I am confused. I am not sure what I am doing. Any help would be appreciated.