If `tan^2((pi-A)/4)+tan^2((pi-B)/4)+tan^2((pi-C)/4)=1` , then ` A B C` is (A) equilateral (B) isosceles (C) scalene (D) none of these

if tan ^(2)""(pi-A)/(4)+tan^(2)""(pi-B)/(4) + tan^(2)""(pi-C)/(4) =1, then DeltaABC is

(1-tan^2(pi/4))/(1+tan^2(pi/4))=?

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 x=tan ((pi)/(4)+A)+tan(B-(pi)/(4)) and y=tan ((pi)/(4)+A)*tan (B-(pi)/(4)) then (x)/(1-y)=

tan^(6)((pi)/(9))-33tan^(4)((pi)/(9))+27tan^(2)((pi)/(9)) is equal to (a)0 (b) sqrt(3)(c)3(d)9

If tan((pi)/(4)+theta)+tan((pi)/(4)-theta)=a, then tan^(2)((pi)/(4)+theta)+tan^(2)((pi)/(4)-theta)=

Q.if tan ^(-1)a+tan^(-1)b+tan^(-1)c=pi, then prove that a+b+c=abc.

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

tan^(-1)((a)/(b))-tan((a-b)/(a+b))=(pi)/(4)