Dear Sanjay,

As given,

Sin A. Sin (A+B)

Using Sin(A+B)=SinA Cos B+CosA Sin B

=SinA (SinA CosB+CosA SinB)

Sin A. Sin (A+B)=Sin2(sin square)A CosB+SinA CosA SinB

I hope you have got your answer.

Good luck with the trignometry.

Hello Sanjay Yadav,

Given= sinA.sin(A+B)

  USING Sin(A+B)=sinAcosB+cosAsinB

   =sinA(sinAcosB+cosAsinB)

   ∴  sinA.sin(A+B)=sin²AcosB+sinAcosAsinB

Thanku.