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2 votes
1 answer
83 views

How to solve the indefinite integral $\int x \cot x\,\mathrm dx$

We can easily solve it with the bounds $0$ to $\frac{\pi}{2}$, but how to solve the indefinite integral? Wolfram Alpha gives the following solution: $$\int x \cot(x)\,\mathrm dx = x \log\left(1 - e^{2 ...
Bikram Kumar's user avatar
3 votes
1 answer
242 views

How to solve $\int\frac{x\arctan x}{x^4+1}dx$ in a practical way

I need to evaluate the following indefinite integral for some other definite integral $$\int\frac{x\arctan x}{x^4+1}dx$$ I found that $$\int_o^\infty\arctan{(e^{-x})}\arctan{(e^{-2x})}dx=\frac{\pi G}{...
phi-rate's user avatar
  • 2,370
1 vote
0 answers
117 views

Closed-form for $\int_0^{a^2} \mathrm{Ei} (-s) \frac{1 - e^s}{s} ds$

In my partial answer to this question: Integral involving polylogarithm and an exponential, I arrive at the integral $$ \int_0^{a^2} \mathrm{Ei} (-s) \frac{1 - e^s}{s} ds , ~~~~ (\ast) $$ where $a \in ...
o0BlueBeast0o's user avatar
3 votes
0 answers
290 views

Evaluate $\int_{1}^{\infty}\frac{\operatorname{Li}_3(-x)\ln(x-1)}{1+x^2}\text{d}x$

Using $$ \operatorname{Li}_3(-x) =-\frac{x}{2}\int_{0}^{1}\frac{\ln^2t}{1+tx} \text{d}t $$ It might be $$ -\frac{1}{2}\int_{0}^{1}\ln^2t \int_{1}^{\infty}\frac{x\ln(x-1)}{(1+tx)(1+x^2)}\text{d}x\text{...
Setness Ramesory's user avatar
5 votes
1 answer
180 views

Is a closed form possible for $\int\frac{\text{Li}_2(x)^2}{x}dx$?

Can $\,\displaystyle\int\frac{\text{Li}_2(x)^2}{x}dx\,$ be calculated by a sum/term of polylogarithm functions and the natural logarithm and polynomials (“closed form”) ? For the special case $\,\...
user90369's user avatar
  • 11.6k
4 votes
2 answers
167 views

I need help computing $\int {\ln x\over 2-x}\, dx$

While integrating $\ln(\sec x)$, at one point I managed to break the integral into two. But I wasn't able to integrate one of those parts. The integral I am having a difficulty with is: $$\int {\ln ...
KKZiomek's user avatar
  • 3,865
3 votes
1 answer
226 views

The indefinite integral $\int\frac{\operatorname{Li}_2(x)}{1+\sqrt{x}}\,dx$: what is the strategy to get such indefinite integral

Here there is an integral that I've found playing with Wolfram Alpha online calculator (thus to me is a curiosity that it has indefinite integral) $$\int\frac{\operatorname{Li}_2(x)}{1+\sqrt{x}}\,dx,\...
user avatar
2 votes
1 answer
182 views

About the integral $\int\arctan\left(\frac{1}{\sinh^2 x}\right)dx$, some idea or feedback

While I was playing with Wolfram Alpha calculator I wondered if it is known a closed-form for $$\int_0^\infty\arctan\left(\frac{1}{\sinh^2 x}\right)dx.\tag{1}$$ Wolfram Alpha provide me the ...
user avatar
1 vote
1 answer
709 views

Integration of a polylogarithm: Is this function known?

I would like to integrate a polylogarithm of a given order $$\int dx \mbox{Li}_{n-1}(x)$$ suppose that the order is $n\le 0$ and $x\in(-\infty,0]$, so the function is bounded. I know that it can be ...
user3209698's user avatar
  • 1,742
6 votes
1 answer
178 views

Evaluating $\int \arccos\bigl(\frac{\cos (x)}{r}\bigr)\sin^2(x){\mathrm dx}$

Following from the previous question Evaluating $\int \arccos\bigl(\frac{\cos(x)}{r}\bigr) \, \mathrm{d}x$ I now need the extra $\sin^2x$ as in the title. Of course one power of $\sin(x)$ is easy, ...
user avatar
8 votes
2 answers
391 views

Closed form for $\int z^n\ln{(z)}\ln{(1-z)}\,\mathrm{d}z$?

Problem. Find an anti-derivative for the following indefinite integral, where $n$ is a non-negative integer: $$\int z^n\ln{\left(z\right)}\ln{\left(1-z\right)}\,\mathrm{d}z=~???$$ My attempt: ...
David H's user avatar
  • 30.7k
4 votes
3 answers
270 views

Tough quadrilogarithm integral

Solve the follolwing definite integral $$\int \frac{\operatorname{Li}_4(z)}{1-z}\, dz$$ It is easy for lower powers!
Zaid Alyafeai's user avatar