Click the Math option and hunt for the symbol. Press and hold the Alt key on your keyboard. I nsert S ymbol.
Letters keyboard to enter sqrt nth root nrt.
Just type Unicode characters on Google then you will get wikipedia link then go there then you will get many Unicode characters including mathematic symbols you can just copy paste them this is the simplest without installing any additional software. Once you insert the symbols you have to make sure your encoding is set to UTF-8 during the save process. Just type letter X or x in your keyboard. Clustered around the numeric keypad like yuppies lurking near Starbucks are various math-symbol keys.