Integration of $\int_{-\infty}^{\infty}\frac{\cos x}{a^2+x^2}dx$
13978
Calculating the integral $\int_0^\infty \frac{\cos x}{1+x^2}\, \mathrm{d}x$ without using complex analysis
94395
Integral: $\int_{-\infty}^{\infty} x^2 e^{-x^2}\mathrm dx$
105494
Gaussian-like integral : $\int_0^{\infty} e^{-x^2} \cos( a x) \ \mathrm{d}x$
53438
I need assistance in integrating $ \frac{x \sin x}{1+(\cos x)^2}$
107296
How do I prove $\int_{-\infty}^{\infty}{\cos(x+a)\over (x+b)^2+1}dx={\pi\over e}{\cos(a-b)}$?
59667
Evaluating $\int_0^\infty\frac{\sin(x)}{x^2+1}\, dx$
145403
Stuck in integration: $\int {\frac{dx}{( 1+\sqrt {x})\sqrt{(x-{x}^2)}}}$
77721
Is it possible to compute $\int_1^{+ \infty} \frac{dx}{x^2(1+e^x)}$?
158147
Calculating $\int_{-\infty}^{\infty}\frac{\sin(ax)}{x}\, dx$ using complex analysis
140386
Integrate $\int {\dfrac{x^2+\left(n-1\right)n}{\left(x\sin x+n\cos x\right)^2}}dx $
51284
$\int_{-\infty}^\infty \frac{e^{ax}}{1+e^x}dx$ with residue calculus
119410
Solution of $\int_0^\infty\frac{\ln(1+{x^2})}{1+{x^2}}$
130736
Integrating $\int^0_\pi \frac{x \sin x}{1+\cos^2 x}$
10319
Definite Integral $\int_{-\infty}^{\infty}\frac{x\sin x}{(x^2+a^2)(x^2+b^2)}\,\mathrm{d}x$
96191
Integral $\int_0^{\infty} \sin(x^2)/x^2\,dx$
156531
Evaluating the integral $\int_{-\infty}^\infty \frac{\sin^2(x)}{x^2}e^{i t x} dx$
89956
Is the integral $\int_0^\infty \frac{\mathrm{d} x}{(1+x^2)(1+x^a)}$ equal for all $a \neq 0$?