class 11

Math

Algebra

Sequences and Series

Let $V_{r}$ denote the sum of the first' ' terms of an arithmetic progression (A.P.) whose first term is'r and the common difference is $(2r−1)$. Let $T_{r}=V_{r+1}−V_{r}−2$ and $Q_{r}=T_{r+1}−T_{r}$ for $r=1,2,…….$ The sum $V_{1}+V_{2}+……+V_{n}$ is