Question

Given sin(A+B) = sinAcosB+cosAsinB, find sin 75

Answer 1

sin75° = sin(45°+30°)
           =sin45°cos30° + sin30°cos45°
           =(1/√2)×(√3/2) + (1/2)×(1/√2)
           =√3/(2√2) + 1/(2√2)
           =(√3+1)/(2√2)