Question

how can i write code for square roots of a number

Answer 1

It is as simple as raising the number to the power of half. For example in python, you could:

num_squared = num ** 0.5

Answer 2

Most languages have libraries that offer such functionality.

What language are you looking for?

Writing a function that calculates the square root without using library functions is a different kind of beast. :)

Answer 3

depends on the language, but in python you can use sqrt() to achieve this.