# This is the limit

Calculus Level 5

$\large \lim_{n\to\infty} \sum_{r=1}^n \frac{\ln(n^2+r^2) - 2\ln(n)}{n} = \ln(2) + \frac\pi2-2$

We are given the value of the limit above. Suppose we consider the limit below

$\large \lim_{n\to\infty} \frac1{n^{2m}} \left[ (n^2+1)(n^2+2^2)(n^2+3^2)\ldots(n^2+n^2)\right]^{\frac mn}$

If this limit equals to $$(ae^{b-a})^m$$ for constant $$m$$ and positive integer $$a$$, find the value of $$b$$.

Clarification: $$\displaystyle e= \lim_{L \to 0} (1+L)^{1/L }$$.

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