Prepare a series to first n terms of the sequence `{(1)/(5),(1)/(7), (1)/(9), (1)/(11),…}`.

Write the first three terms of the sequence a_(n)=(-1)^(n-1) 5^(n+1)

STATEMENT-1 : The sum of reciprocals of first n terms of the series 1 + (1)/(3) + (1)/(5) + (1)/(7) + (1)/(9) + … "is" n^(2) and STATEMENT-2 : A sequence is said to be H.P. if the reciprocals of its terms are in A.P.

STATEMENT-1 : The sum of reciprocals of first n terms of the series 1 + (1)/(3) + (1)/(5) + (1)/(7) + (1)/(9) + … "is" n^(2) and STATEMENT-2 : A sequence is said to be H.P. if the reciprocals of its terms are in A.P.

Write the first three terms of the sequence a_n=(-1)^(n-1)5^(n+1) .

Find t_n if first four terms of the sequence {t_n} are 1,1/4,1/9,1/16,…

Sum to n terms of the series (1)/(2 . 5) +(1)/(5 . 8)+(1)/(8 . 11)+..=

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)+ ...

Find the sum to n terms of the series: (1)/(1.3)+(1)/(3.5)+(1)/(5.7)+...

find the sum upto n terms of the series (1)/(1*3)+(1)/(3*5)+(1)/(5*7)+...