Verify the identity. StartFraction sine left parenthesis alpha plus beta right parenthesis Over sine alpha cosine beta EndFraction equals 1 plus cotangent alpha tangent beta sin(+) sincos =1+cottan Solution sin(+)/sincos =1+cottan sin( + ) = sin()cos() + cos()sin() LHS ======> sin()cos()/sincos + cos()sin()/sincos = 1 + cot()*tan() = RHS.