How to prove that the power $b^n$ is an irrational number, where $b$ is an integer greater than $1$ and $n$ is an irrational number?
$b^n$ is irrational, where $b>1$ is a integer and $n$ is an irrational
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number-theory
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14This is not true. A counterexample is $b = 2$, $n = \log_2 3$, $b^n = 3$. – 2010-11-14
1 Answers
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The Gelfond-Schneider theorem shows that if you assume that $n$ is algebraic, then $b^n$ is indeed irrational, in fact transcendental! You can even take $b$ to be algebraic.
So we can ask whether there's an easy proof that $ b^n $ is irrational for b integral and n an algebraic irrational.