Python Square Root – The sqrt() Function with Examples

How to find the square root using the Python sqrt() function

In this tutorial, you will learn how to find the square root of a number using the sqrt() function in Python. This tutorial will also show you how to find the square root without using the sqrt() function in Python.

• Absolute value in Python

Syntax of the sqrt() Function

The syntax of the sqrt() function is as follows:

math.sqrt(number)

Argument

• Number: The number for which you want to find the square root

Remarks

• To use the sqrt() function, you must import the math module.
• The argument number must be a positive number.

Square Root Examples

Example 1: Find the square root of 4

The following example is a sample program that finds the square root of 4:

import math
#find the square root of 4
square_root = math.sqrt(4)
print("The square root of 4 is", square_root)

Output:

The square root of 4 is 2.0

Example 2: Find the square root of 5

Below is a sample program that finds the square root of 5:

import math
#find the square root of 5
square_root = math.sqrt(5)
print("The square root of 5 is", square_root)

Output:

The square root of 5 is 2.23606797749979

Example 3: Find the square root of -5

Below is a sample program to find the square root of -5:

import math
#find the square root of -5
square_root = math.sqrt(-5)
print("The square root of -5 is", square_root)

Output:

ValueError: math domain error

The number -5 is a negative value, so Python produces an error.

Example 4: Find the square root without using sqrt()

The following is a sample program that finds the square root of a number without using any built-in functions.

import math
#find the square root of 25 without using math module (sqrt)
square_root = 25**(1/2)
print("The square root of 25 is", square_root)

Output:

The square root of 25 is 5.0

Summary

In this tutorial, you learned how to find the square root of a number using Python's sqrt() function. This tutorial also showed how to find the square root without using Python's sqrt().