If `A+B+C=pi`, prove that
`(cosA)/(sin B sinC)+(cos B)/(sin C sinA)+(cos C)/(sin A sinB)=2`.

If A+B+C=pi , prove that : (cosA)/(sinb sinC) + (cosB)/(sinC sin) + (cosC)/(sinA sinB) =2 .

If A+B+C=pi , prove that : cosA sinB sinC +cosB sinC sinA+cosC sinA sinB=1+cosA cosB cosC .

If A+B+C=pi , prove that : sin2A+sin2B+sin2C=4sinA sinB sinC

If A+B+C=pi , prove that : sinA cosB cosC +sinB cosC cosA + sinC cosA cosB = sinA sinB sinC .

If A+B+C=pi , prove that : sinA+sinB+sinC= 4cos, A/2 cos, B/2 cos, C/2

Prove that: sin(B-C)cos(A-D) + sin(C-A) cos (B-D) + sin(A-B) cos(C-D) = 0

If A+B+C=pi/2 , prove that: sin2A + sin2B+sin2C = 4cosA cosB cosC

In any triangle A B C , prove that: (a^2sin(B-C))/(sinB+ sin C)+(b^2sin(C-A))/(sinC+ sin A)+(c^2sin(A-B))/(sinA+ sin B)=0

If A+B+C = pi , prove that : cosA+cosB + cosC = 1+4sinA/2sinB/2sinC/2 .

In any DeltaABC , prove that (sin B)/(sin C) = (c-a cos B)/(b-a cos C)