# Calculus + Infinity + Limit

Calculus Level 4

For positive integer $$m$$, if $$\displaystyle \lim_{m\to\infty} \int_{-\infty}^{\infty} \dfrac{dx}{1+x^2+x^4+ \cdots + x^{2m}} = \dfrac AB$$, where $$A$$ and $$B$$ are coprime positive integers, find $$A+B$$.

×