import matplotlib.pyplot as plt
import numpy as np

debut = 0
fin = 4
pas = 0.1
x = np.arange(debut,fin,pas)
f = np.exp(x)
plt.plot(x,f,"r") # trace une courbe rouge
plt.xlabel('x')
plt.ylabel('f(x) = exp(x)')

def Euler (h,n):
    x=0
    y=1
    Lx=[x]
    Ly=[y]
    for i in range(n):
        x=x+h
        Lx.append(x)
        y=y+h*y
        Ly.append(y)
    plt.plot(Lx,Ly,"b")
    plt.show()
    return(Lx,Ly)
Euler(1,4)