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Which function dominates x^p or p^x

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4 votes
I'm assuming
p\in\mathbb R is fixed. First note that
x^p=p^x when
x=p.

We can rewrite each expression as


x^p=e^(p\ln x)

p^x=e^(x\ln p)

Now to compare we only need to consider the exponents. It's easy to show that
x>\ln x for all
x>0, so it follows that
x^p<p^x so long as
x>p.
User Stefan Ticu
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