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

A, B, C, D are the four angles, taken in order of a cyclic quadrilateral. Prove that, cot A + cot B + cot C + cot D = 0

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

If ABCD be a cyclic quadrilateral,-prove that cos A + cos B + cos C + cos D = 0

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

If A, B, C, D are the four angle taken in order of a cyclic quadrilateral, prove that (ii) cos (180^(@) - A) + cos (180^(@) + B) + cos (180^(@) + C) - sin (90^(@) + D) = 0

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

If A,B,C,D are the four angles taken in order of a cyclic quadrilateral prove that (i)tan A+tan B+tan C+tan D=0 (ii) cos(180^(@)-A)+cos(180^(@)+B)+cos(180-C^(@))-sin(90+D)tan(A+B)+tan(C+D)=0tan(A+B)+tan(C+D)=0

If A, B, C, D be the angles of a cyclic quadrilateral, taken in order, prove that : cos A + cos B + cos C+ cos D = 0 .

If A,B,C,D are angles of a cyclic quadrilateral,prove that cos A+cos B+cos C+cos D=0

If ABCD is a cyclic quadrilateral, then the value of cos A - cos B + cos C - cos D =