I have this proof that I cannot figure out. If anyone could give me a little headstart that would be great. I am still struggling to fully grasp the concepts so maximum explanation is useful please.

Also I dont know how to make the perp symbol that looks like an upside down T so ill use an L instead.

V^L=V perp

WcV means W is a subspace of V

Suppose that A is a real symmetric n x n matrix. Show that if V is

a subspace of Rn and that A(V)cV, then A(V^L)cV^L.

Any help??!?!

Thanks