`cot A + cot (60^(@) + A) + cot (120^(@) +A) = 3 cot 3 A.`

Prove the following identity: cot A+cot(60^0+A)+cot(120^0+A)=3cot3A

If A = 1/1 cot ^(-1) (1/1) + 1/2 cot^(-1) (1/2) + 1/3 cot ^(-1) ( 1/3) " and " B = 1 cot^(-1) ( 1) + 2 cot^(-1) (2) + 3 cot^(-1) (3) " then " |B - A| " is equal to " (api)/b + c/d cot ^(-1) (3) where a,b,c,d in N are in their lowest form , find ( b -a - c - d)

The value of cot36^(@)cot72^(@), is

Prove the following identities : (1 + sin A)/ (cosec A - cot A) - (1 - sin A)/ (cosec A + cot A) = 2(1 + cot A)

Prove that: cotA+"cot"(60^0+A)-cot(60^0-A)=3cot3A

Prove that: cotA+"cot"(60^0+A)-cot(60^0-A)=3cot3A

cot 6^0 cot 42^0 cot 66^0 cot 78^0=1

Sum of infinite terms of the series cot^(-1) ( 1^(2) + 3/4) + cot^(-1) ( 2^(2) + 3/4) + cot^(-1) ( 3^(2) + 3/4) + ... is

In any DeltaABC , prove that cot (A/2) + cot (B/2) + cot (C/2) = (a+b+c)/(b+c-a) cot (A/2)

cot A =1/2 (cot ""(A)/(2) - tan "" (A)/(2)).