UnsolvedIntegral: What is the Integral of x^(x) dx?

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Hello.

I was walking from home and thought to myself

What would the integral of x^(x) dx be?

And I momentarily thought

[X^(x+1)] / (x+1)

But that can't be it. lol

Does anyone have an idea? Oh just in case you guys become frantic and mad about it and go like (This is a homework problem, think about it yourself a little bit more :devil:), I assure, you, this isn't a homework problem so please chill and give me some ideas.
 
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I'm pretty sure there is no integral for this that is defined by elementary functions. If you look around the forum I think I've read at least one or two with the same question.
 
I thought that sounded familiar, too. A problem that's come up periodically is inverting the function x*e^x. This is the Lambert W function (non-elementary). But this is not that. It may have a name - but giving something a name doesn't mean you understand it better. It just makes it easier to google for it.
 
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Even Mathematica does not have a solution to this conundrum. :biggrin:

Mathematica could not find a formula for your integral. Most likely this means that no formula exists.

http://integrals.wolfram.com/
 
Of course its easier if you have these things in terms of the standard family of functions. For this particular case we recognise that its a "special" exponential function which can of course be written as follows.

x^x=e^{x\ln(x)}

Its actually relatively easy to differentiate but as yet I can't find any method of integrating, but perhaps someone with more experience would be able to find something.
 
Prove $$\int\limits_0^{\sqrt2/4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx = \frac{\pi^2}{8}.$$ Let $$I = \int\limits_0^{\sqrt 2 / 4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx. \tag{1}$$ The representation integral of ##\arcsin## is $$\arcsin u = \int\limits_{0}^{1} \frac{\mathrm dt}{\sqrt{1-t^2}}, \qquad 0 \leqslant u \leqslant 1.$$ Plugging identity above into ##(1)## with ##u...
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