Question

Q1. product of sin ( A + B ). sin ( A - B ) is:

I ) sin^2 A- sin^2 B
II ) cos^2 A- cos^2 B
III ) cos^2 B- sin^2 B
IV ) cos^2 A+ cos^2 B

Answer 1

Answer:

sin(A+B).sin(A−B)

=Sin^2 a-sin^b

ans) a

Answer 2

Answer:

$\huge{\bf{\underline{\red{Answer :}}}}$

I ) sin^2 A- sin^2 B

II ) cos^2 A- cos^2 B

$\rm\underline\bold{III ) cos^2 A- sin^2 B\red{{\checkmark}}}$

IV ) cos^2 A+ cos^2 B

Explanation:-

sin ( A + B ) , sin ( A - B )

= [ sin (A) cos (B) + cos (A) sin (B) ] [ sin (A) cos

= sin²Acos²A - cos²Asin²A

= sin²A [ 1 - sin²B] - [ 1 - sin²A] sin²B

= sin²A - sin²Asin²B - sin²B + sin²Asin²B

= sin²A - sin²B