Let the sequence a_1,a_2,a_3, ,a_ 2n form an AP, then a_1^2-a_2^2+a_3^2- -a_ 2n ^2 is equal to

JEE Main Mathematics question

Let the sequence form an AP, then is equal to

Answer: (A)

Pair the terms: . Summing over gives S_{2n}$=-d·

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Question ID VK-021634