Prove that: `("sin"(A-B))/(cos A s in B)+(s i ln(B-C))/(cos B cos C)+("sin"(C-A))/(cos C cos A)=0`

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

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

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

(sin (BC)) / (cos B cos C) + (sin (CA)) / (cos C cos A) + (sin (AB)) / (cos A cos B) = 0

(cos A)/(sin B sin C)+(cos B)/(sin C sin A)+(cos C)/(sin A sin B)=2

Prove that : (sin 2A+sin 2B + sin 2C)/(cos A + cos B + cos C-1) = 8 cos(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)

Prove that sin(A+B+C)=sin A cos B cos C+cos A sin B cos C+cos A cos B sin C-sin A sin B sin Ccos(A+B+C)=cos A cos B cos C-cos A sin B sin C-sin A cos B sin C-sin A sin B cos C

(cos A) / (c sin B) + (cos B) / (a sin C) + (cos C) / (b sin A) =