请问这个代码该如何实现

import numpy as np
import matplotlib.pyplot as plt

x = np.linspace(-10, 12)
y = x*x-x*2+3

plt.plot(x, y, 'b',label='y = x^2-2x+3')
plt.plot(1, 2, 'r-o')

plt.legend()
plt.show()