Hello. I am yashar and I am a student i work on java and i try to write square root function on my own self but now i stuck in it and dont know how to do that. i know i can use it with this Math.sqrt() but i want to how this statement actually works.

What is Modular multiplicative inverse how can I calculate Modular multiplicative inverse for a given number?

What is modular exponentiation how can I find the modular exponentiation of a given number?