How to type square root on formulas?

[-Physician]

The title says it all , i need to type square root on ## formulas

 

[Char. Limit]

Try \sqrt{stuff}.

 

[-Physician]

Ohhh, i forgot the \, i tried sqrt without the \, hmm let me try
$\sqrt{9}$

 

[-Physician]

Thank you very much:)