Fie funcția:
[tex]\text{radical}:[0,+\infty)\to [0,+\infty),\quad \text{radical}(x) = x^\big{\frac{1}{2}}\\ \\ \text{radical}(x)} = x^\big{\frac{1}{2}} = \sqrt{x}[/tex]
Prin urmare:
[tex]\text{radical}(x) \text{ se noteaza } \sqrt{x}\text{, inseamna }x^\big{\frac{1}{2}} \text{ cand } x\geq 0\\ \text{si i se spune: "radical din x"}[/tex]
