Prove that: `(sin(B-C))/(cosBcosC)+(sin(C-A))/(cosCcosA)+(sin(A-B))/(cosAcosB)=0`

Prove that (a^2sin(B-C))/(sinb+sinC)+(b^2"sin"(C-A))/(sinC+sinA)+(c^2"sin"(A-B))/(sinA+sinB)=0

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

(sin(A - B))/(cos A cos B) + (sin (B - C))/( cos B cos C) + (sin(C - A))/(cos C cos A) is

Prove that (sin (A-B))/(sin (A+B))=(a^(2)-b^(2))/(c^(2))

Prove that sin (A+B)= sin A cos B + cos A sin B.

Show that suma sin(B-C) =0

In a Delta ABC, prove that (a sin(B - C))/(b^(2) - c^(2)) = (b sin (C - A))/(c^(2) - a^(2)) = (c sin (A - B))/(a^(2) - b^(2))

Prove that sin (A+B) sin (A-B)=cos^(2) B-cos^(2) A

Show that cos[(B-C)/2]=(b+c)/a sin(A/2)