Sunday, 21 August 2016

improper integrals - Show that $int_{-infty}^{infty}frac{x^2dx}{(x^2+1)^2(x^2+2x+2)}=frac{7pi}{50}$

Show that



$$\int_{-\infty}^{\infty}\frac{x^2dx}{(x^2+1)^2(x^2+2x+2)}=\frac{7\pi}{50} $$



So I figured since it's an improper integral I should change the limits




$$\lim_{m_1\to-\infty}\int_{m_1}^{0}\frac{x^2dx}{(x^2+1)^2(x^2+2x+2)}+ \lim_{m_2\to\infty}\int_{0}^{m_2}\frac{x^2dx}{(x^2+1)^2(x^2+2x+2)}$$



I'm however not sure how to evaluate this. Any help would be great - thanks.

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