import numpy as np
import pylab as pl

C = np.sqrt(12)
x_vals = np.linspace(0, 1, 1000)
psi_sqrd = C ** 2 * (x_vals ** 2 - x_vals ** 3)

pl.rcParams['figure.dpi'] = 300
pl.plot(x_vals, psi_sqrd)
pl.title("|Psi|^2")
pl.xlabel("x")
pl.ylabel("|Psi|^2")
pl.vlines(0.6, ymin=0, ymax=1.8, label="<x>", color="red")
pl.vlines(2 / 3, ymin=0, ymax=1.8, label="x_mp", color="green")
pl.legend()
pl.grid()
pl.show()