import numpy as np
import matplotlib.pyplot as plt

N=...
E=...
f=...
u0=...
t=np.linspace(....,....,....)
u=u0
for i in range(N):
    u=u+...........
#Tracé de la fonction u(t)
plt.plot(...,...)
plt.grid()
plt.xlabel('...')
plt.ylabel('...')
plt.show()