How should I calculate $\int_0^\infty e^{-\frac{1}{2}(x^2+a^2/x^2)}\,dx$
70830
How to evaluate $\int_{0}^{\infty}\exp(-x^2-1/x^2)dx$?
8705
Evaluation of $\sum_{x=0}^\infty e^{-x^2}$
70013
How to calculate $\int \frac{x^2 }{(x^2+1)^2} dx$?
4287
Proving $\int_{0}^{\infty} \mathrm{e}^{-x^2} dx = \frac{\sqrt \pi}{2}$
765
$\int_0^\infty \frac{\log(x)}{x^2+\alpha^2}$ using residues
67450
How do you integrate $e^{x^2}$?
40537
How to prove $\int_0^\infty e^{-x^2}cos(2bx) dx = \frac{\sqrt{\pi}}{2} e^{-b^2}$
57224
Compute $\int_0^\infty \frac{dx}{1+x^3}$
59667
Evaluating $\int_0^\infty\frac{\sin(x)}{x^2+1}\, dx$
32312
Evaluating the integral $\int \frac{x^2+x}{(e^x+x+1)^2}dx$
112621
Finding $\int_{0}^{\infty} \frac{e^{3x}-e^x}{x(e^{3x}+1)(e^x+1)} dx$
21390
How to integrate $\int_0^{\infty} \frac{e^{ax} - e^{bx}}{(1 + e^{ax})(1+ e^{bx})}dx$ where $a,b > 0$.
39798
Computing $\lim_{n \to \infty} \int_0^{n^2} e^{-x^2}n\sin\frac{x}{n}\,dx$?
109901
Computing $\int_0^\infty\frac1{(x+1)(x+2)\cdots(x+n)}\mathrm dx $
124463
Integral from $0$ to $\infty$ of $\ln(x)/e^x$
128572
How $\int_{-\infty}^{\infty}\frac{dx}{1+x^2}$ exists?
81831
Evaluate $\int_0^{\infty}\frac{\log x}{1+e^x}\,dx$