SinA+sinB+sinC= cosA+cosB+cosC=0 prove that1)cos2A+cos2B+cos2C=0 2)sin2A+sin2B+sin2C=0 3)cos(A+B)+cos(B+c)+cos(C+A)=0​4) summation cos4A = 2summation (B+C)5)summation sin^2A=3/2=summation cos*2A

Priya , 6 Years ago

Grade 12th pass