The sum 20 terms of a series whose rth term is given by `T_r=(-1)^r((r^2+r+1)/(r!))` is

Find the sum of firs 100 terms of the series whose general term is given by T_(r)=(r^(2)+1)r! .

The sum of infinite terms of the sequence whose r^("th") term is given by t_(r)=(1)/((r+1)(r+3)) is equal to

Write the sum of n term fo a series whose r^(t h) term is: r+2^rdot

find the sum of n terms of an AP whose rth term is ( 5r+1)

Find the sum of the n terms of the sequence whose general term is given by a_r=(r^5+6r^4+11r^3+6r^2+4r+6)/(r^4+6r^3+11r^2+6r)

Find the sum of n terms of the series the r^(th) term of which is (2r+1)2^(r).

sum_(r=1)^(20) r (2r+1)=

The rth term of a series is given by t_(r)=(r)/(1+r^(2)+r_(n)^(4)), then lim(n rarr oo)sum_(r=1)^(n)(t_(r))

Prove that the sum of n terms of GP with first term a and common ratio r is given by S_(n)=a(r^(n)-1)/(r-1)

Sum of the series Sigma_(r=1)^(n) rlog((r+1)/(r)) is