Question

if A=30 and B=60 verify that :

1] sin (A+B) = sinA cosB + cosA sinB

Answer 1

sin (30+60) = sin30×cos60 + cos30×sin60
sin90 = (1/2 × 1/2) + root 3/2 × root 3/2
1 = 1/4 + 3/4
1 = 1

Answer 2

LHS

sin ( A + B) = sin(30+60)=sin90= 1

RHS

SinA CosB + CosA SinB
=Sin30 × Cos60 + Cos30 × Sin 60
=1/2 × 1/2 + √3/ 2 × √3/2
=1/4 + 3/4
=4/4
=1


Therefore, LHS = RHS