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.

(iii) a cosA + b cos B + c cos C = 4R sin A sin B sinC

If A+B+C=pi/2 prove the following (i) sin 2A+sin 2B +sin 2C=4 cos A cos B cos C (ii) cos 2A +cos 2B+cos 2C=1+4 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 .

If A+B +C = 270^@ , then cos 2A + cos 2B +cos 2C +4sin A sin B sin C=

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