`tan^-1 (1/3)+tan^-1 (1/7)+tan^-1 (1/13)+…+tan^-1(1/(1+n+n^2))+….to oo` is equal to (A) `(2pi)/3` (B) 0 (C) `pi/2` (D) `pi/4`

Prove that tan^-1(1/8)+2tan^-1(1/3)+tan^-1(1/57)=pi/4

The sum of the series tan ^(-1)"" (1)/( 1 + 1 + 1 ^(2)) + tan ^(-1)"" (1)/( 1 + 2 + 2 ^(2)) + tan ^(-1) ""(1)/( 1 + 3 + 3 ^(2)) +... is equal to : a) pi/4 b) pi/2 c) pi/3 d) pi/6

tan^(-1) . 3/5 +tan^(-1) . 1/4 = pi/2

Prove that : tan^(-1)(1/2) + tan^(-1)(1/3) = tan^(-1)(3/5) + tan^(-1)(1/4) = pi/4

Prove that : tan^(-1)(1/2) + tan^(-1)(1/3) = tan^(-1)(3/5) + tan^(-1)(1/4) = pi/4

Prove that tan^(- 1)(1/3)+tan^(- 1)(1/7)+tan^(- 1)(1/13)+..........+tan^-1 (1/(n^2+n+1))+......oo = pi/4

Prove that tan^(- 1)(1/3)+tan^(- 1)(1/7)+tan^(- 1)(1/13)+..........+tan^-1 (1/(n^2+n+1))+......oo =pi/4

Prove that tan^(- 1)(1/3)+tan^(- 1)(1/7)+tan^(- 1)(1/13)+..........+tan^-1 (1/(n^2+n+1))+......oo =pi/4