If `cosA+coaB+cosC=sinA+sinB+sinC=0` the values of `(cos3A+cos3B+cosC)/(cos(A+B+C))`

If cosA+cosB+cosC=0,sinA+sinB+sinC=0andA+B+C=180^(@) then the value of cos3A+cos3B+cos3C is :

If cosA+cosB+cosC=0,sinA+sinB+sinC=0andA+B+C=180^(@) then the value of cos3A+cos3B+cos3C is :

If A+B+C= pi and cosA+cosB+cosC=0=sinA+sinB+sinC then cos3A+cos3B+cos3C=

If sinA+sinB+sinC=3 , then the value of cosA+cosB+cosC is equal to

If cosA+cosB+cosC=0=sinA+sinB+sinC then cos^(2)((A-B)/2)=

If sin A +sin B +sinC =3 then what is cos A + cosB+cosC equal to ?

cos^(2)A+cos^(2)B-cos^(2)C=1-2sinA sinB cosC

Let 0 le a,b,c,d le pi where b,c are not complementary such that 2cosa + 6cos b + 7cosc + 9cosd = 0 and 2sina-6sinb + 7 sinc-9sind=0 .Then the value of (cos(a+d))/(cos(b+c)) =