# How to simplify an expression with a radical sign nesting in a radical sign

RatDenmon is a function that can rationalize the denominator.
• What output are you looking for? Which alternative/simpler form would you use for Sqrt[5 + Sqrt[5]]? – Szabolcs Mar 22 '15 at 1:56
• RootReduce will give you a polynomial which has this number as a root. ToRadicals converts it back. – Szabolcs Mar 22 '15 at 2:07