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I started wondering about this the other day. Since the following have their own alternate representations. $\begin{align*} \displaystyle\large x+x=2x & \ \frac{x}{x}=1 & xx=x^2\end{align*}$

Can $x^x$ be represented in some other way? Thanks.

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    $x/x=1$ is not true when $x=0$, careful.2012-10-07

2 Answers 2

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Yes, it's called tetration. We can write $x^x$ as $^{2}x$.

There's actually a whole chain of these iterated operators, such as the (rather) famous Knuth up-arrow notation. The page I linked to has quite a few examples if you are interested.

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$e^{x\log(x)}$

This is a nice way to represent it if you want to differentiate it, since you can then just apply the standard differentiation rules.

Something like $x^{x^x}$ will be represented as $e^{e^{x\log(x)}\log(x)}$