---

A[i][j]=2*R[i]/(h)**2
        elif j==i+1 or j==i-1:
            A[i][j]=-R[i]/(h)**2
    return A

n=5
x0=0
xn=1
h=(xn-x0)/(n-1)
X=[i*h for i in range(n)]
R=[((23+24)/2)*x*(1-x) for x in X]
A=matr_jest(n,h,R)
E=0.01
import numpy as np
V0=np.ones(n)
Lambda0=np.sqrt(sum([v**2 for v in V0]))
A=np.array(A)
A[0],A[n-1]=0,0
A[:,0],A[:,n-1]=0,0
A[0][0],A[n-1][n-1]=1,1
invA=np.linalg.inv(A)
k=Lambda0
while k>E:
    y1=np.dot(1/Lambda0,V0)
    V1=np.dot(invA,y1)
    Lambda1=np.sqrt(sum([v**2 for v in V1]))
    k=abs(Lambda1-Lambda0)
    V0=V1
    Lambda0=Lambda1
Pkr=round(1/Lambda1,3)
Pkr