"sin(a+63градусов)+sin(a-57градусов) / 2cos(a-87градусов)" / в низу

Question

"sin(a+63градусов)+sin(a-57градусов) / 2cos(a-87градусов)" / в низу

Answer 1

2sin(a+3)cos60/2cos(a-90+3)=2sin(a+3)*0.5/2sin(a+3)=0,5