v) `tan(A/2)tan(B/2)+tan(B/2)tan(C/2)+tan(C/2)tan(A/2)=1`

If A+B+C=pi , prove that : tan( A/2) tan (B/2) + tan (B/2 )tan (C/2)+ tan( C/2) tan (A/2) =1

(tan(B/2)-tan(C/2))/(tan(B/2)+tan(C/2))

In triangle ABC, if |[1,1,1], [cot (A/2), cot(B/2), cot(C/2)], [tan(B/2)+tan(C/2), tan(C/2)+ tan(A/2), tan(A/2)+ tan(B/2)]| then the triangle must be (A) Equilateral (B) Isoceless (C) Right Angle (D) none of these

If A+B+C=pi, show that : tan.(A)/(2)tan.(B)/(2)+tan.(B)/(2)tan.(C)/(2)+tan.(C)/(2)tan.(A)/(2)=1 Hence deduce that : cot.(A)/(2)+cot.(B)/(2)+.cot.(C)/(2)=cot.(A)/(2).cot.(B)/(2)tan.(C)/(2) .

In Delta ABC if tan((A)/(2))tan((B)/(2))+tan((B)/(2))tan((C)/(2))=(2)/(3) then a+c

s^(2)tan((A)/(2))tan((B)/(2))tan((C)/(2))

In triangle ABC, if 1,1cot(A)/(2),cot(B)/(2)tan(B)/(2)+tan(C)/(2)quad tan(B)/(2)+tan(A)/(2)quad tan(A)/(2)+tan(B)/(2) obtuse angled d.none of these

Prove that: tan(A+B)tan(A-B)=(tan^(2)A-tan^(2)B)/(1-tan^(2)A tan^(2)B)

In /_ABC with usual notations,if a,b,c are in A.P.then the numerical value of tan((A)/(2))tan((B)/(2))+tan((B)/(2))tan((C)/(2)) is

If alpha+beta+gamma=2pi, then (A) tan(alpha/2)+tan(beta/2)+tan(gamma/2)=tan(alpha/2)tan(beta/2)tan(gamma/2) (B) tan(alpha/2)tan(beta/2)+tan(beta/2)tan(gamma/2)+tan(gamma/2)tan(alpha/2)=1 (C) tan(alpha/2)+tan(beta/2)+tan(gamma/2)=tan(alpha/2)tan(beta/2)tan(gamma/2) (D) none of these