Recent content by dajt

Thanks. We only have to show closure under + and . We did cover that, but for some reason the lecturer isn't asking for it in the proof. To show the zero vector is part of W, I could just show something like: u = (0, 0, 0). 0 - 2(0) + 0 = 0, so u is an element of W. Is that right? That...

OK, thanks. I see your point that I just restated what is known. Is my answer valid and provides proof by showing you can ignore k, or doesn't it prove anything? Regards, David.

Homework Statement Let W = { (x, y, z) | x - 2y + z = 0 } Is W a subspace of R3? Homework Equations The Attempt at a Solution Using another post here I tried the following to show W is closed under addition: 1. Let u = (x, y, z) and v = (i, j , k). u and v are both in W...