Square root of a number is a value, which, when multiplied by itself results in the value. Square root is represented by √ symbol. Thus,
√9 = 3, since 3 * 3 = 9.
In this article, we will look at different ways to calculate square root with python.

Method 1: Using ** operator
`**` operator is used to raise a number to some power. Square root of a number is the number raised to a power of 1/2.
Thus,

Square root = (Number)1/2

Or

Square root = (Number)0.5

Using this formula, python program to get square root can be written as

```# read number
num = int(input('Enter a number: '))
sqrt = num ** 0.5
print('Square root is:', sqrt)```

Output is

Enter a number: 12
Square root is: 3.4641016151377544

Method 2: Using pow() function
Python’s math module has a `pow()` function which takes 2 arguments:
1. Number whose square root needs to be calculated.
2. Power to which the number should be raised.

As stated above, square root of a number can be calculated by raising it to power 1/2 or 0.5. Hence, 0.5 supplied as second argument to `pow()` results in square root of number. Example,

```import math

num = int(input('Enter a number: '))
# raise number to power of 0.5
sqrt = math.pow(num,0.5)
print('Square root is:', sqrt)
```

Output is

Enter a number: 25
Square root is: 5.0

Method 3: Using isqrt() function
`isqrt()` function of `math` module calculates the square root of the values supplied as argument and returns the integer or whole number part of square root. Example,

```import math

num = int(input('Enter a number: '))
sqrt = math.isqrt(num)
print('Square root is:', sqrt)```

Output of this program is

Enter a number: 27
Square root is 5

Note that the square root of 25 is 5.2(rounded off) but `isqrt()` returns its integer part, that is, 5.
Square root of complex numbers
Complex numbers are represented as x + yj
where,
x and y are real numbers and j is imaginary unit.

It is possible to find the square root of a complex number using `sqrt()` function of python’s `cmath` module.
`sqrt()` accepts a complex number as argument and returns its square root.
Real and imaginary parts of the square root can be accessed using `real` and `imag` fields of this square root respectively.
Example program is given below

```import cmath

# define a complex number
num = 5 + 4j
# find its square root
sqrt = cmath.sqrt(num)
print('Square root is {0:0.2f} + {1:0.2f}j'.format(sqrt.real,sqrt.imag))```

This prints

Square root is 2.39 + 0.84j

Square root values are formatted to 2 decimal places.

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