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

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

If sum_(r=1)^(n)T_(r)=(n(n+1)(n+2))/(6), then the value of sum_(r=1)^(oo)((1)/(T_(r))) is equal to

The value of sum _(r =1) ^(oo) (8r)/(4r ^(4) +1) is equal to :

The value of sum _(r =1) ^(oo) (8r)/(4r ^(4) +1) is equal to :

The value of sum_(r=1)^(15) (r2^(r))/((r+2)!) is equal to (a) ((17)!-2^(16))/((17)!) (b) ((18)!2^(17))/((18)!) (c) ((16)!-2^(15))/((16)!) (d) ((15)!-2^(14))/((15)!)

The value of sum_(x=1)^(n)(-1)^(r+1)(C(n,r))/(r+1) is equal to

The sum sum_(k=1)^oocot^(-1)(2k^2) equals

The sum sum_(k=1)^oocot^(-1)(2k^2) equals

sum _(r = 2) ^(oo) (1)/(r ^(2) - 1) is equal to :