import numpy as np
import matplotlib.pyplot as plt

def f(x) :
    N = 1000
    s = 1/(x**2)
    for k in range(N) :
        s += 1/(k+x)**2+1/(k-x)**2
    return s
    
X = np.linspace(10.1,10.9,100)
Y = [f(x) for x in X]
plt.plot(X,Y)
plt.show()

# X = np.linspace(-5,5,500)
# Y = [f(x)-np.pi**2/(np.sin(np.pi*x)**2) for x in X]
# plt.plot(X,Y)
# plt.show()