Calculate 2x2 Matrix Inverse

Write a Python function that calculates the inverse of a 2x2 matrix. Return 'None' if the matrix is not invertible.

Example:

Input:

matrix = [[4, 7], [2, 6]]

Output:

[[0.6, -0.7], [-0.2, 0.4]]

Reasoning:

The inverse of a 2x2 matrix [a, b], [c, d] is given by (1/(ad-bc)) * [d, -b], [-c, a], provided ad-bc is not zero.

Code:

import numpy as np

def inverse_2x2(matrix):
    m = np.array(matrix)

    if np.linalg.det(m) == 0:
        return None
    
    return np.linalg.inv(m)