Find the sum of the series: `(2^(2)+4^(2)+6^(2)+8^(2)+ ..."to n terms"

1.	Find the sum of the series: `(2^(2)+4^(2)+6^(2)+8^(2)+ ..."to n terms")`
Answer» Correct Answer - `(2)/(3)n(n+1)(2n+1)` `T_(n)=[2+(n-1)xx2}^(2)=(2n)^(2)=4n^(2).` `therefore S_(n)=sum_(k=1)^(n)T_(k)=4(sum_(k=1)^(n)k^(2))=4xx(1)/(6)n(n+1)(2n+1).`

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