Prove that for any two subspaces W_{1}and W_{2 }of an inner product space V, we have

a) (W_{1}+ W_{2})^⊥ = W_{1}^⊥ ∩ W_{2}^⊥ and

b) (W_{1}∩ W_{2})^⊥ = W_{1}^⊥ + W_{2}^⊥

Hint: The second follows from the first- you may use the fact that (W^⊥)^⊥ = W.

Any help would be greatly appreciated!