Question

(sinA+cosA)*(sinB-cosB)=sin (B-A)-cos (B+A)

Answer 1

sinAsinB-sibAcosB+cosAsinB-coaAcosB=
=(cosAsinB-sinAcosB)-(coaAcosB-sinAsinB)=sin(B-A)-cos(A+B)

Answer 2

спасибо большой

Answer 3

$(sin A+cos A)(sin B-cos B)=\ =sin Asin B-cos Acos B+cos Asin B-sin Acos B=\ =cos Asin B-sin Acos B-(cos Acos B-sin Asin B)=\ =sin(B-A)-cos(B+A)$