Consider a complex inner product space with norm induced by the inner product. If x and y are members of the space, prove that
$(x, y) - (y, x) = \frac{i}{2} (||x + iy||^2 - ||x - iy||^2)$
and
$(x, y) + (y, x) = \frac{1}{2} (||x + y||^2 - ||x - y||^2)$
