a cos A+b cos B+c cos C=2a sin B sin C

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

Prove that a cos A+b cos B+c cos C=4R sin A sin B sin C

Prove that a cos A + b cos B + c cos C = 4 R sin A sin B sin C.

Prove that a cos A + b cos B + c cos C = 4 R sin A sin B sin C.

Prove that a cos A + b cos B + c cos C = 4 R sin A sin B sin C.

Prove that sin(A+B+C)=sin A cos B cos C+cos A sin B cos C+cos A cos B sin C-sin A sin B sin Ccos(A+B+C)=cos A cos B cos C-cos A sin B sin C-sin A cos B sin C-sin A sin B cos C

Expand cos ( A + B + C). Hence prove that cos A cos B cos C = sin A sin B cos C + sin B sin C cos A + sin C sin A cos B, if A + B + C = (pi)/(2) .

Prove that a cos A + b cos B + c cos C = 4R sin A sin B sin C

If A+B+C=(pi)/(2) , then prove that cos 2A + cos 2B + cos 2C=1+4 sin A sin B sin C .