If A, B, C are angles of a triangle , prove that `cos 2A+cos 2B -cos 2C=1-4 sin A sin B cos C`

If A, B, C are angles of a triangle , prove that cos 2A - cos 2B + cos 2C =1 -4 sin A cos B sin C

If A, B, C are angles of a triangle , prove that sin 2A+sin 2B-sin 2C=4cos Acos B sin C

cos2B + cos2A-cos2C = 1-4sin A sin B cos C

IF A,B,C are angles of a triangle , Prove that cos2A+cos 2B+cos 2C=-4cosAcosBcosC-1

If A, B, C are angles in a triangle , then prove that cos^(2)A+cos^(2)B-cos^(2)C=1-2sin Asin Bcos C.

If A + B + C =pi , prove that : cos 2A + cos 2B -cos 2C= 1-4sin A sin B cos C .

In a triangleABC, prove that a cos A+b cos B+c cos C=2a sin B sin C

For any triangle ABC,prove that a cos A+b cos B+c cos C=2a sin B sin C

In any triangle ABC, prove that: a cos A+b cos B+c cos C=2a sin B sin C

If A, B, C are angles in a triangle , prove that sin A+ sin B -sin C =4sin. (A)/(2)sin. (B)/(2) cos. (C)/(2)