If `underset(r=1)overset(n)SigmaT_r=n/8(n+1)(n+2)(n+3)` then find `underset(r=1)overset(n)Sigma1/T_r`

If Sigma_(r=1)^(n) T_r=n/8(n+1)(n+2)(n+3) then find Sigma_(r=1)^(n) 1/T_r

underset(r=0)overset(n)(sum)sin^(2)""(rpi)/(n) is equal to

Find the value of underset(r = 1)overset(10)sum underset(s = 1)overset(10)sum tan^(-1) ((r)/(s))

Prove that underset(rles)(underset(r=0)overset(s)(sum)underset(s=1)overset(n)(sum))""^(n)C_(s) ""^(s)C_(r)=3^(n)-1 .

Prove that underset(r = 0) overset (n)(sum) 3^(r) ""^(n)C_(r) = 4^(n)

If sum_(r=1)^n T_r=(3^n-1), then find the sum of sum_(r=1)^n1/(T_r) .

If sum_(r=1)^n T_r=n(2n^2+9n+13), then find the sum sum_(r=1)^nsqrt(T_r)dot

If the sum of the series Sigma_(n=0)^(oo) r^(n),|r|le 1 is s, then find the sum of the series Sigma_(n=0)^(oo) r^(2n),|r|le 1