import numpy as np
import matplotlib.pyplot as plt

a = 0.5


riktig = np.cos(a)

hL = []
dL = []

print(np.sin(a)/2)
for h in 10.**(-np.arange(1,17)):
    d = (np.sin(a+h)-np.sin(a))/h
    hL.append(h)
    dL.append(d-riktig)
    print(f"{h:10e}   {d:10e}    {(d-riktig):10e}")


#plt.plot(np.log(hL),np.log(np.abs(dL)),'o')
plt.loglog(hL,np.abs(dL),'o')
plt.show()