" 9."sin^(2)(A-B)-sin^(2)(A+B)+cos2A cos2B=cos(2A+2B)

If : A+B+C=pi, "then"" "sin ^(2) A +sin^(2)B - sin ^(2)C= A) 2 cos A * cos B * sin C B) 2 cos B * cos C * sin A C) 2 sin A * sin B * cos C D) 2 sin B * sin C * cos A

Prove the following identities: tan^(2)A-tan^(2)B=(cos^(2)B-cos^(2)A)/(cos^(2)B cos^(2)A)=(sin^(2)A-sin^(2)B)/(cos^(2)A cos^(2)B)(sin A-sin B)/(cos A+cos B)+(cos A-cos B)/(sin A+sin B)=0

(sin ^ (2) A-sin ^ (2) B) / (sin A cos A-sin B cos B) = tan (A + B)

sin^(2) A cos^(2)B + cos ^(2) A sin^(2) B + sin^(2) A sin^(2) B+ cos^(2) A cos^(2) B=

If A + B + C = 180^(@) , prove that sin^(2)A + sin^(2)B + sin^(2) C = 2 + 2 cos A cos B cos C

sin ^ (2) A cos ^ (2) B + cos ^ (2) A sin ^ (2) B + sin ^ (2) A sin ^ (2) B + cos ^ (2) A cos ^ (2) B =

Prove that sin(A+B)sin(A-B)=sin^(2)A-sin^(2)B=cos^(2)B-cos^(2)A

Prove the following tan^2A- tan^ 2B=(sin^2A-sin^2B)/(cos^2A*cos^2B) =(cos^2B-cos^2A) /(cos^2A*cos^2B)

Prove that: sin^(2)A=cos^(2)(A-B)+cos^(2)B-2cos(A-B)cos A cos B

If A, B , C are angles in a triangle, then prove that sin ^(2)A+ sin ^(2)B+sin^(2)C=2+2 cos A cos B cos C