Show that if V is a subspace of R n, then V must contain the zero vector.
The Attempt at a Solution
If a set V of vectors is a subspace of Rn, then, V must contain the zero vector, must be closed under addition, and, closed under scalar multiplication.
Let u = (u1,u2,u3....un), Let w = (w1,w2,w3...wn) and k scalar is a real number.
for ku = (0,0,0,.....0n), k = 0 (is this a valid?)
for u+w = 0, (u1+w1, u2+w2,u3+w3....un+wn) = (0,0,0,.....0n)
i.e., u1+w1 = 0, then u1=-w1
if u1 = 1,then w1=-1 (is this valid?)