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JEE MainMathematicsEasyLimits

lim⁡n→∞\mspace2mu12+22+32+………+n2n3=\lim_{n \rightarrow \infty}\mspace{2mu}\frac{1^{2} + 2^{2} + 3^{2} + \ldots\ldots\ldots + n^{2}}{n^{3}} =

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lim⁡n→∞\mspace2mu12+22+32+………+n2n3=lim⁡n→∞\mspace2mun(n+1)(2n+1)6n3\lim_{n \rightarrow \infty}\mspace{2mu}\frac{1^{2} + 2^{2} + 3^{2} + \ldots\ldots\ldots + n^{2}}{n^{3}} = \lim_{n \rightarrow \infty}\mspace{2mu}\frac{n(n + 1)(2n + 1)}{6n^{3}}
=16lim⁡n→∞\mspace2mu1(1+1n)(2+1n)1=16(1+0)(2+0)=13= \frac{1}{6}\lim_{n \rightarrow \infty}\mspace{2mu}\frac{1\left( 1 + \frac{1}{n} \right)\left( 2 + \frac{1}{n} \right)}{1} = \frac{1}{6}(1 + 0)(2 + 0) = \frac{1}{3}

Source: Grass-G / M-19 Mathematics Paper 28 Nov Fourth.docx

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