Let S_K= 1+2+ +K K and _ j=1 ^nS_j^2= nA (Bn^2+Cn+D ), where A,B,C,D N and A has least value. Then

JEE Main Mathematics question

Let and \sum_{j=1}^nS_j^2=\frac nA\left(Bn^2+Cn+D\right), where and has least value. Then

Answer: (A)

, so . With least, , , , : is

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Question ID VK-022065