import numpy as np
import numpy.linalg as alg

def matrice(n,a,b):
    M=np.zeros((n+1,n+1))
    for i in range(1,n+1):
        M[i,i]=-i*(a+b)
        M[i,i-1]=i-1-n
        M[i-1,i]=i*a*b
    return M

def propre(n,a,b):
    return alg.eig(matrice(n,a,b))

a=1
b=-1
n=2
print(matrice(n,a,b))
print(propre(n,a,b))