In any triangle ABC, show that : `2a cos (B/2) cos (C/2) = (a+b+c) sin (A/2)`

In any triangle ABC, show that : 2a sin (B/2) sin (C/2)=(b+c-a) sin (A/2)

For triangle ABC, show that: sin((A+B)/(2))-cos(C)/(2)=0

In a triangle ABC, prove that (a) cos(A + B) + cos C = 0 (b) tan( (A+B)/2)= cot(C/ 2)

For triangle ABC, show that "sin"(A+B)/2="cos"C/2

In any triangle ABC ,prove that (a-b cos C)/( c-b cos A ) = (sin C ) /( sin A)

if A, B and C are interior angles of a triangle ABC, then show that cos((B+C)/2) = sin (A/2)

if A, B and C are interior angles of a triangle ABC, then show that cos((B+C)/2) = sin (A/2)

For triangle ABC, show that : (i) "sin" (A + B)/(2) = "cos" (C)/(2) (ii) "tan" (B + C)/(2) = "cot" (A)/(2)

In any Delta ABC, show that cos A+ cos B+ cos C = (1+ (r )/(R )).

For any triangle ABC, prove that a(cosC-cos B)\ =\ 2\ (b - c)\ cos^2(A/2)