RootReduce

RootReduce[expr] attempts to reduce expr to a single Root object.

Examples

Reduce a sum of roots:

RootReduce[Sqrt[2] + Sqrt[3]]
(* Root[1 - 10 #1^2 + #1^4 &, 4] *)

Simplify a root expression:

RootReduce[Sqrt[2]^3]
(* 2 Sqrt[2] *)

Please visit the official Wolfram Language Reference for more details.