# -*- coding:utf-8 -*-

import matplotlib.pyplot as plt
import numpy as np

start=-4
final= 0
step = 0.1

x = np.arange(start, final+step, step)
y1 = -x**2-4*x + 3
#y2 = -(x-1)**2 +2

plt.xlabel("x")
plt.ylabel("y")
plt.plot(x, y1)
#plt.plot(x, y2)

plt.grid()
plt.show()