# -*- coding: utf-8 -*-
"""
Created on Wed Apr  1 08:53:24 2026

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

X = np.linspace(-0.5,0.5,20000)

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

plt.plot(X,Y,"k")
plt.plot(X,X**2,"b:")
plt.plot(X,-X**2,"b:")
# plt.plot(X,Y2,"b:")
plt.axis("scaled")