If `cosA+cosB+cosC=0, then cos3A+cos3B+cos3C` is equal to

cos^2 A + cos^2 B +cos^2 C=1+2cosA cosB cosC .

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

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 A,B and C are angles of a triangle then the determinant |(-1,cosC,cosB),(cosC,-1,cosA),(cosB,cosA,-1)| is equal to

If A,B and C are angles of a triangle, then the determinant |{:(-1,cosC,cosB),(cosC,-1,cosA),(cosB,cosA,-1):}| is equal to "........."