Where can I find a root sign on a word using a phone?

1.Press +<=> (where ever you want to insert square root, you will get equation box, and then) . 

2.To insert Square root symbol (√) in Word, type 221A and then press Alt+X to convert the alt code into a square root symbol. 

3.Go to Insert. 

4.press Alt+ equal to Then type /sqrt.

 5.Click on Insert from the top menu. 

6.Go in symbol.

Done!! Now you have that symbol