Question

sin^2(30+A)-sin^2(30-A)=√3/2sin2A​

Answer 1

Answer:

Using sin

2

x=1−cos

2

x

∴1−2sin

2

30

°

=1−2×

4

1

⟹1−2sin

2

30

°

=1−

2

1

=

2

1

From the given options, cos60

°

=

2

1

Therefore, 1−2sin

2

30

°

=cos60

°

.

Answer 2

Step-by-step explanation:

sin^2(30°+ A)- Sin^2(30°-A)

(sin(30+A) +sin(30-A)) (sin(30+A -sin(30-A)}

=2sin30cosA*2co30sinA

=4*1/2* √3/2 sinAcosA

= √3/2*2sinAcosA

= √3/2 sin2A=RHS