[" 9.In any triangle "ABC" ,prove that "],[qquad (a+b+c)(tan(A)/(2)+tan(B)/(2))=2c cot(C)/(2)]

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

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

In any Delta ABC, prove that: (a+b-c)/(a+b+c)=tan((A)/(2))tan((B)/(2))

In any triangle ABC, prove that following: (c)/(a-b)=(tan((A)/(2))+tan((B)/(2)))/(tan((A)/(2))-tan((B)/(2)))

In triangle ABC ,prove that the maximum value of tan(A)/(2)tan(B)/(2)tan(C)/(2)is(R)/(2s)

In any triangle ABC, prove that: (b-c)cot(A)/(2)+(c-a)cot(B)/(2)+(a-b)cot(C)/(2)=0

In any triangle ABC, prove that following: (c)/(a+b)=(1-tan((A)/(2))tan((B)/(2)))/(1+tan((A)/(2))tan((B)/(2)))

In any triangle ABC, prove that : tan frac (B+C-A)(2)= cot A .

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