Prove the following: $ \gcd(a^n,b^n) = 1 \Leftrightarrow \gcd(a,b)=1,\;$ where $ a,b,n \in \mathbb{N}$.
I can show one side by using Fermat's Theorem and breaking them down into unique factorizations and then putting them to the power of $n$ but how do go the other way?