Question

if A=30 degree verify that sin2A=2sin A cos A

Answer 1

Sin2(30)=sin60=root 3 /2=lhs
2sin30cos30=2×root 3/2×1/2
=root e/2=rhs

Lhs=rhs

Answer 2

Sin2A =sin2×30

=Sin60

=√3/2

So,

2sinA.cosA=2sin30× cos30

=2×1/2 ×√3/2

=√3/2

Hence sin2A= 2sinA.cosA