" The value of "cot(sum_(n=1)^(23)cot^(-1)(1+sum_(k=1)^(n)2k))" is "

The value of cot(sum_(n=1)^(23)cot^-1(1+sum_(k=1)^n2k)) is

The value of cot(sum_(n=1)^(2)cot^(-1)(1+sum_(k=1)^(n)2k)) is (a) (23)/(25) (b) (25)/(23) (c) (23)/(24) (d) (25)/(26)

The value of cot sum_(n=1)^(19)(cot^(-1)(1+sum_(p=1)^(n)2p)) is equal to ( a )(21)/(19) (b) (19)/(21)(c)-(19)/(21) (d) -(21)/(19)

The value of cot sum_(n=1)^(19)(cot^(-1)(1+sum_(p=1)^(n)2p)) is equal to (a) (21)/(19) (b) (19)/(21) (c) -(19)/(21) (d) -(21)/(19)

The value of cot sum_(n=1)^(oo)cot^(-1)((2)/(n^(2))sum_(n=1)^(n)k^(3))

The value of sum_(r=1)^(n+1)(sum_(k=1)^(n)C(k,r-1))=

Evaluate : sum_(k=1)^n (2^k+3^(k-1))