text: # Mathematics > Linear Algebra Foundations > Eigenvalue of matrix #2
  # Basic problems related to eigenvalues.
  #
  # https://www.hackerrank.com/challenges/eigenvalue-of-matrix-2/problem
  #
  
  import numpy as np
  
  M = np.matrix([[1, 2],
                 [2, 4]])
  
  print(np.linalg.eigvals(M))
  
  I = np.identity(np.linalg.matrix_rank(M))
  
  for λ in np.linalg.eigvals(M):
      print(np.linalg.det(M - λ * I))