# -*- coding: utf-8 -*-
"""
Created on Tue Mar 31 11:47:18 2026

@author: François Coulombeau
"""
import numpy as np
import matplotlib.pyplot as plt

X = np.linspace(-1,1,2000)

Y = X - 2*X**2*np.sin(1/X)
Y2 = X

plt.plot(X,Y,"k")
plt.plot(X,Y2,"b:")
plt.axis("scaled")