10.7.31 Calculating integrals of a real variable using residues
Condition: Calculate the integral. \[ \int_{-\infty}^{\infty} \frac{d x}{\left(x^{2}+1\right)^{2}\left(x^{2}+81\right)} \]
Here you can find calculations of proper and improper integrals of a real variable using residues, using various techniques.