Name given to a numerical ou algebraic expression expressed using the symbol \(\sqrt{\hphantom{9}}\) or \(\sqrt[n]{\hphantom{9}}\).

### Educational notes

- The \(\sqrt{\hphantom{9}}\) symbol is also called a “radical”, but has no meaning on its own.
- The \(\sqrt{\hphantom{9}}\) symbol is read as “radical” or “positive square root of…”
- In the expression \(\sqrt[n]{\hphantom{9}}\), the number \(n\) is called the index of the radical; the expression is called a radical of order \(n\).

The horizontal bar that groups the radicand is called the vinculum. **Similar radicals**are radicals with the same index or the same order.- Christoff Rudolff is credited with having introduced the radical symbol.