#!/usr/bin/python3
import numpy as np
import math
import matplotlib.pyplot as plt
import mpl_toolkits.mplot3d as Axes3D

def f(x,y):
    return ((x-1)**2+y**2)


x = np.linspace(-2,2,100)
y = np.linspace(-2,2,100)
X,Y = np.meshgrid(x,y)

fig = plt.figure()
ax = fig.add_subplot(111,projection='3d')
surf = ax.plot_surface(X,Y, f(X,Y))
plt.show()