$\int_0^3 (x^2 + 1){\rm d}\left[x\right]$ where [.] is gif
121406
Interesting Integration with respect to $[x]$ where $[\cdot]$ is greatest integer function
49944
Integral $\int_1^3 \frac{\log x}{x^2+3}dx$
86367
Computing $f(x)$ if $\int_1^{xy} f(t) dt = y \int_1^x f(t) dt + x\int_1^y f(t) dt$ and $f(1) = 3$
15625
Computing $\int_0^\infty\mathrm{d} x\frac{x}{e^x+1}$ with contour integration
38511
Evaluation of $\int\frac{1}{x^2.(x^4+1)^{\frac{3}{4}}}dx$
5034
A closed form of $\int_0^1\frac{\ln\ln\left({1}/{x}\right)}{x^2-x+1}\mathrm dx$
122361
Evaluate $\int_0^1\left(\frac{1}{\ln x} + \frac{1}{1-x}\right)^2 \mathrm dx$
53748
Find maximum value of $\int_{0}^{1}\left(f(x)\right)^3dx$
45806
Finding $\lim\limits_{n \rightarrow \infty}\left(\int_0^1(f(x))^n\,\mathrm dx\right)^\frac{1}{n}$ for continuous $f:[0,1]\to[0,\infty)$
98838
How to evaluate $\int_0^1 \frac{\ln(x+1)}{x^2+1} dx$
80553
Show that,$\int_0^\pi \left|\frac{\sin nx}{x}\right|\mathrm{d}x \ge \frac{2}{\pi}\left(1+\frac12+\cdots+\frac{1}{n}\right)$
21522
This integral is defined ? $\displaystyle\int_0^0\frac 1x\:dx$
78008
A conjectured closed form of $\int\limits_0^\infty\frac{x-1}{\sqrt{2^x-1}\ \ln\left(2^x-1\right)}dx$
107119
A logarithmic integral $\int^1_0 \frac{\log\left(\frac{1+x}{1-x}\right)}{x\sqrt{1-x^2}}\,dx$
143734
Evaluating $\int \frac{\sin\left(x\right)}{1+x^2}dx$
144039
Computing $ \int_0^{\infty} \frac{ \sqrt [3] {x+1}-\sqrt [3] {x}}{\sqrt{x}} \mathrm dx$
57659
Evaluate $\int_{\left | z \right |=3} (e^{z}-1)dz/(z(z-1)(z-i))$