# Real integrals using Complex integration

What is the criterion for choosing a contour in the complex plane for the evaluation of real integrals of the form $\int_{-\infty}^{\infty}f(x)dx$? For example $\int_{-\infty}^{\infty}\sin{x^2}dx$.

• There are techniques often used by people. You must decide whether the path you choose is easy to calculate. – eccstartup Aug 12 '13 at 10:31