Summary  
This chapter demonstrates how to define a matrix in Python, compute its eigenvalues and eigenvectors using numpy’s eig function, and validate each eigenpair by checking that A @ v equals λ * v.  

General domain of usage  
Scientific computing

## Computing Eigenvalues and Eigenvectors

import numpy as np
from numpy.linalg import eig

# Define matrix A (square matrix)
A = np.array([[2, 1],
              [1, 2]])

# Solve for eigenvalues and eigenvectors
eigenvalues, eigenvectors = eig(A)

# Print eigenvalues and eigenvectors
print(f'Eigenvalues:\n{eigenvalues}')
print(f'Eigenvectors:\n{eigenvectors}')

`eig()` from the `numpy` library computes the solutions to the equation:

$$
A v = \lambda v
$$

* `eigenvalues`: a list of scalars $$\lambda$$ that scale eigenvectors;
* `eigenvectors`: columns representing $$v$$ (directions that don't change under transformation).

import numpy as np
from numpy.linalg import eig

# Define matrix A (square matrix)
A = np.array([[2, 1],
              [1, 2]])

# Solve for eigenvalues and eigenvectors
eigenvalues, eigenvectors = eig(A)

# Verify that A @ v = λ * v for each eigenpair
for i in range(len(eigenvalues)):
    print(f'Pair {i + 1}:')
    λ = eigenvalues[i]
    v = eigenvectors[:, i].reshape(-1, 1)
    print(f'A * v:\n{A @ v}')
    print(f'lambda * v:\n{λ * v}')

This checks if:

$$
A v = \lambda v
$$

The two sides should match closely, which confirms correctness. This is how we validate theoretical properties numerically.

This course distills the essentials of Python's math module, focusing on trigonometric functions, logarithmic operations, and mathematical constants. Learners will gain hands-on experience using Python to perform these standard mathematical computations, ideal for beginners seeking practical skills with the math module.

Implementing Eigenvectors & Eigenvalues in Python

Computing Eigenvalues and Eigenvectors

Validating Each Pair (Key Step)