Possible Duplicate:
How to evaluate this integral?
Let $b>0$. Evaluate the next value of integral:
$$\begin{equation} \int_{-\infty} ^{\infty} \dfrac{\cos x}{x^2 + b^2} \ dx \end{equation}$$
Possible Duplicate:
How to evaluate this integral?
Let $b>0$. Evaluate the next value of integral:
$$\begin{equation} \int_{-\infty} ^{\infty} \dfrac{\cos x}{x^2 + b^2} \ dx \end{equation}$$