19. Prove that `sin(A +B) sin(A-B)+sin(B+C)sin(B-C) + sin(C+A) sin(C-A)=0`

What is the value of sin(A+B)sin(A-B)+sin(B+C)sin(B-C)+sin(C+A)sin(C-A) ?

In a DeltaABC , prove that : sin3A sin(B-C)+sin3B sin(C-A) + sin3C sin (A-B)=0 .

Prove that (sin (A - B))/( sin A sin B ) + ( sin (B -C))/( sin B sin C ) + (sin (C - A))/( sin C sin A) =0

In triangle ABC, prove that sin(B+C-A)+sin(C+A-B)+sin(A+B-C)=4sin A sin B sin C .

sin(B+C-A)+sin(C+A-B)+sin(A+B-C)=4sin A sin B sin C

If A + B + C =180^@ , prove that : sin (B+C-A) + sin(C+ A-B)+ sin(A +B-C)=4sin A sinB sinC .

Prove that: ("sin"(A-B))/(sin A sin B)+("sin"(B-C))/(sin B sin C)+("sin"(C-A))/(sin C sin A)=0

Prove that: (sin(A-B))/(s in As in B)+(sin(B-C))/(s in Bs in C)+(sin(C-A))/(s in Cs in A)=0

Show that: sin A sin(B-C)+sin B sin(C-A)+sin C sin(A-B)=0

If A + B + C = 180^(@) , prove that sin(B + C - A) + sin (C + A - B) + sin(A + B + C) = 4 sin A sin B sin C.