If `A+B+C =180^@` then `cos A+cosB-cos C=`

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

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

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

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

If A+B+C=180^0,\ then s e c A(cos B cos C-sin B sin C) is equal to:

If A+ B+C= 180^(@) " then " cos 2A+ cos 2B + cos 2C+ 1=

If A+B+c=180^(@), then sec A(cos B cos C-sin B sin C) is equal to 0 b.-1 c.1d .none of these