[(cot^(2)15-1)/(cot^(2)15+1)=?],[(a)(1)/(2)]

Cot^(-1)(4/3)-Cot^(-1)(15/8)=

2cot(cot^(-1)(3)+cot^(-1)(7)+cot^(-1)(13)+cot^(-1)(21)) has the value

If the sum of first 16 terms of the series s=cot^(-1)(2^(2)+(1)/(2))+cot^(-1)(2^(3)+(1)/(2^(2)))+cot^(-1)(2^(4)+(1)/(2^(3)))+ up to terms is cot^(-1)((1+2^(n))/(2(2^(16)-1))), then find the value of n.

(1 - cot^(2)45^(@))/(1 + cot^(2)45^(@)) =

(1 - cot^(2)45^(@))/(1 + cot^(2)45^(@)) =

The value of 2(cot^(-1))(1)/(2)-(cot^(-1))(4)/(3) is

If cot^(-1) ( alpha) = cot^(-1)(2) + cot^(-1)(8) + cot^(-1)(18) + cot ^(-1)(32) + "…………" upto 100 terms , then alpha is :

2cot^(-1)5+cot^(-1)7+2cot^(-1)8=(pi)/(4)

The sum of infinite terms of the series cot^(-1)(2^(2)+1/2)+cot^(-1)(2^(3)+1/2^(2))+cot^(-1)(2^(4)+1/2^(3))+…=cot^(-1)k then k =

The value of sum_(r=1)^(oo)cot^(-1)((r^(2))/(2)+(15)/(8)) is equal to