If `A+B+C = (3pi)/(2),then cos2A+cos2B+cos2C=`

If A+B+C=(3 pi)/(2), then cos2A+cos2B+cos2C is equal to a.1-4cos A cos B cos C b.4sin A sin B sin C c.1+2cos A cos B cos Cd.1-4sin A sin B sin C

If A+B+C=(3 pi)/(2), then cos2A+cos2B+cos2C is equal to (A)1-4cos A cos B cos C(B)4sin A sin B sin C(C)1+42cos A cos B cos C(D)1-4sin A sin B sin C

If A+B+C=(3 pi)/(2), then cos2A+cos2B+cos2C is equal to (i) 1-4cos A cos B cos C( is 4sin A sin B sin C (iii) 1+2cos A cos B cos C(iv)1-4sin A sin B sin C

If A+B+C=(3pi)/2 . Then cos 2A +cos 2B+cos2C is equal to ................. A) 1-4 cos A cos B cos C B) 4 sin A sin B sin C C) 1+2 cos A cos B cos C D) 1-4 sin A sin B sin C

If A+B+C=3pi/2 . Then cos 2A +cos 2B+cos2C is equal to

If A+B+C=(3pi)/(2), prove that cos 2A+ cos 2B+ cos 2C=1-4 sin A sin B sin C .

If A+B+C=pi , then cos2A+cos2B+cos2C=

If A+B+C=pi , then cos 2A+cos 2B+cos 2C=