If `|[a+ib,c+id],[-c+id,a-ib]|**|[alpha-ibeta,gamma-idelta],[-gamma-idelta,alpha+ibeta]|= |[A-iB,C-iD],[-C-iD,A+iB]| ` write down the values of A,B,C,D , hence show that the producrs of sums , each of four squares , can be expressed as the sum of four squares