If `A+B+C=180^(@)`, then `(cos2A+cos2B+cos2C+1)/(cos A cos B cos C)`

If A+B+C=180^(@) then cos2A+cos2B+cos2C=1-4cos A cos B cos C 2.If A+B+C=0 then cos A+cos B+cos C=-1+4(cos A)/(2)(cos B)/(2)(cos C)/(2)

If A+B+C=90^(@) then (cos2A+cos2B+cos2C-1)/(sin A sin B sin C)=

Theorem 2:cos2A+cos2B+cos2C=-1-4cos A cos B cos C

If A+B+C=180^(@) then cos A+cos B-cos C=

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

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

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

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

If A+B+C=270^(@), then cos2A+cos2B+cos2C+4sin A sin B sin C=

A + B + C = 180 ^ (@) rArr cos2A + cos2B + cos2C =