What conditions of $x$ such that $e^{x^e} \ge x^{e^x}$ ?
2026-03-27 02:01:28.1774576888
What conditions of $x$ such that $e^{x^e} \ge x^{e^x}$?
74 Views Asked by Bumbble Comm https://math.techqa.club/user/bumbble-comm/detail At
2
One might start by noticing that $x^{e^x}$ is undefined for $x<0$. Assuming we are looking at the domain $x\ge0$, one can see that for $x>e$,
$$x^{e^x}>e^{e^x}>e^{x^e}$$
So if it were to hold true, $x\le e$. At $x=e$, they are trivially equal.
One might also notice that
$$x^{e^x}=e^{e^x\ln(x)}$$
So the problem reduces to solving
$$e^x\ln(x)\le x^e$$
When $x\le1$, we trivially have
$$e^x\ln(x)\le0\le x^e$$
For $1<x<e$, take the log of both sides to get
$$x+\ln(\ln(x))\le e\ln(x)$$
This may be done by considering
$$f(x)=e\ln(x)-x-\ln(\ln(x))$$
And noting that
$$f(e)=0,f'(x)<0\forall x\in(1,e)$$