Find the sum series: `tan^-1 (1/3)+tan^-1 (1/7)+tan^-1(1/13)+…to oo`

Find the sum of the series tan^(-1) 1/2+tan^(-1) 1/8+tan^(-1) 1/18+tan^(-1) 1/32+...oo

If "S" is the sum of the first "10" terms of the series tan "^(-1)((1)/(3))+tan^(-1)((1)/(7))+tan^(-1)((1)/(13))+tan^(-1)((1)/(21))+.... ,then "tan(S)" is equal to:

PT tan^(-1)(3/4)+tan^(-1)(1/3)=tan^(-1)(13/9)

tan^(-1)7-tan^(-1)5=tan^(-1)(1)/(18)

Find the sum of the series tan^(-1)((1)/(2))+tan^(-1)((1)/(2))+tan^(-1)((1)/(18))+tan^(-1)((1)/(32))+

tan^(-1)2-tan^(-1)1=tan^(-1)(1)/(3)

Sum to n terms the series tan^-1 (1/(1+1+1^2))+tan^-1 (1/(1+2+2^2))+tan^-1 (1/(1+3+3^2))+…

tan^(-1)7-tan^(-1)5=tan^(-1)(1/18)

Find the value of : 4(2 tan^(-1) . 1/3 +tan^(-1). 1/7)