import numpy as np

import matplotlib.pyplot as plt

x=np.linspace(0,6,100)

y=np.cos(2*np.pi*x)*np.exp(-x)+0.8

plt.plot(x,y,'k',color='r',linewidth=3,linestyle="-")

plt.show()

import numpy as np

import matplotlib.pyplot as plt

x = np.arange(0,  3  * np.pi,  0.1)

y = np.sin(x)

plt.title("sine wave form")

plt.plot(x, y)

plt.show()