Show that the volume of a triclinic unit cell of sides a, b, and c and angles a, B3, and y is V= abc (1- cos2a- cos2B – cos2y+ 2 cos a cos B cos y)1/2 Use this expression to derive expressions for monoclinic and orthorhombic unit cells. For the derivation, it may be helpful to use the result from vector analysis that V= a-b x c and to calculate VZ initially.