But I can't seem to find a simple manipulation for P and Q to get the second formula all I can find is
(P dot e_{1})(Q dot e_{1})  (P dot e_{2})(Q dot e_{2})
Where e_{1} = (1,0) and e_{2} = (0,1)
Again the back of my book gives the expanded for of cos([tex]\phi[/tex] + [tex]\theta[/tex]) so I don't even know what they are trying to say.
