`1/(r(r+1)` Find the sum to infinity terms.

Find the sum Sigma_(r=1)^(n) r/((r+1)!) . Also, find the sum of infinite terms.

Find the sum Sigma_(r=1)^(n) r/((r+1)!) . Also, find the sum of infinite terms.

Find the sum Sigma_(r=1)^(n) r/((r+1)!) . Also, find the sum of infinite terms.

Find the sum to infinity of the series 1 + (1+a)r+(1 + a + a ^(2))r^(2) + … where 0 lt a, r le 1

Find the sum to infinity of the series 1 + (1+a)r+(1 + a + a ^(2))r^(2) + … where 0 lt a, r le 1

The rth term of a series is (2r + 1)2^(r ) , find the sum of first n terms of the series.

If |r|<1, then the sum of infinite terms of G.P is

Sum to infinity of a GP is 15 and the sum to infinity of their squares is 45 .If a is the first term and r is the common ratio then the sum of the first 5 terms of the AP with first term a and common difference 3r is

In a series, the rth term is (2r + 1).2r. Find the sum of 1st n terms of this series.

Find the nth term sum of n terms and sum to infinity terms of the series (1)/(2.5)+(1)/(5.8)+ (1)/(8.11)+ ...