Question

Найдите значение выражения

Answer 1

sin(a-b)+2cosa*sinb=sina*cosb-sinb*cosa+2cosa*sinb=sina*cosb+sinb*cosa=sin(a+b)
sin(86+64)=sin150=sin(180-30)=sin30=1/2

Answer 2

=sin AcosB-cos Asin B+2cos AsinB=sinAcosB+cosAsinB=sin (A+B)=sin (86+64)=sin150=sin30=1/2