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

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Homework Help Overview

The discussion revolves around the integral of the function x^(x) with respect to x. Participants explore the nature of this integral and its relation to known functions.

Discussion Character

  • Exploratory, Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants discuss the possibility of expressing the integral in terms of elementary functions, with some suggesting that it may not exist in that form. Others reference related concepts such as the Lambert W function and the differentiation of the function.

Discussion Status

The conversation is ongoing, with various perspectives being shared. Some participants have noted the lack of a known solution, while others have provided insights into the nature of the function and its differentiation.

Contextual Notes

There is an emphasis on the integral not being a homework problem, and participants are encouraged to explore the topic without the pressure of homework constraints.

asd1249jf
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.
 
Last edited:
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.
 

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