" Compore that tan "A" tan "B" tan "C" tan "D

If (" cos " (A+B))/(" cos " (A-B)) =(" sin " (C+D))/(" sin " (C -D)) , prove that tan A tan B tan C + tan D=0

If (cos(A-B))/(cos(A+B))+(cos(C+D))/(cos(C-D))=0, prove tht tan A tan B tan C tan D=-1

Given that A = B +C. prove that tan A - tan B - tan C = tan A tan B tan C.

If (cos (AB)) / (cos (A + B)) + (cos (C + D)) / (cos (CD)) = 0 Prove that tan A tan B tan C tan D = -1

If ( cos (A+B))/( cos (A-B)) =( sin (C+D))/( sin (C -D)) then prove that tan A tan B tan C + tan D=0 ................. A) 0 B) -1 C) sqrt3 D) 1

If A + B + C = 180^(@) , then prove that tan A + tan B + tan C = tan A tan B tan C.

If A + B + C =180^@ , prove that : tan A + tan B + tan C = tan A tan B tan C .

If A + B + C = pi , prove that tan A+ tan B + tan C = tan A tan B tan C

If A + B + C = 180^(@) , then prove that tan A + tan B + tan C = tan A tan B tan C.

If A, B, C, D are the four angle taken in order of a cyclic quadrilateral, prove that (i) tan A + tan B + tan C + tan D = 0