from scipy.integrate import quad
import numpy as np
import matplotlib.pyplot as plt

x = np.linspace(-4, 4, num = 100)

constant = 1.0 / np.sqrt(2 * np.pi)
pdf_normal_distribution = constant * np.exp((-x ** 2) / 2.0)

fig, ax = plt.subplots(figsize=(10, 5))

ax.plot(x, pdf_normal_distribution)
ax.set_ylim(0)
ax.set_title('Normal Distribution', size=20)
ax.set_ylabel('Probability Density', size=20)

plt.show()