`tan((A+B)/(2))="cot"(C)/(2)`

In triangle ABC , "tan"(A)/(2),"tan"(B)/(2),"tan"(C)/(2) are in H.P ., then the value of "cot"(A)/(2)xx"cot"(C)/(2) is equal to

If A+B+C=pi , then tan((A)/(2))tan((B)/(2))+tan((B)/(2))tan((C)/(2))+tan((C)/(2))tan((A)/(2)) is equal to a) (pi)/(6) b)3 c)2 d)1

If cosx=(2cosy-1)/(2-cosy) , where x,y in(0,pi) , then "tan"(x)/(2)"cot"(y)/(2) is equal to

If costheta=(cosalpha-cosbeta)/(1-cosalphacosbeta) . prove that one of the value of "tan"(theta)/(2) is "tan"(alpha)/(2)"cot"(beta)/(2) .

Prove that tan((A-B)/2)= (a-b)/(a+b)cot frac(c)(2)

In a DeltaABC , if tan""(A)/(2)=(5)/(6),tan""(C )/(2)=(2)/(5) , then a)a, c, b are in AP b) a, b, c are in GP c)b, a, c are in AP d)a, b, c are in AP

cos ^(-1) ((3+5 cos x )/(5+3 cos x )) is equal to : a) tan ^(-1) ((1)/(2) tan ""(x)/(2)) b) 2 tan ^(-1) (2 tan ""(x)/(2)) c) (1)/(2) tan ^(-1) (2 tan ""(x)/(2)) d) 2 tan ^(-1) ((1)/(2) tan ""(x)/(2))

In any triangle ABC, prove that tan((B-C)/2)=(b-c)/(b+c) cot frac (A)(2)

In a /_\ABC , prove that tan((B-C)/2)=(b-c)/(b+c)cotfrac(A)(2)