Plots of nonlinear functions

import os
import matplotlib.pyplot as plt
import numpy as np
os.chdir('/home/vg/Downloads/projects/ex15')
os.getcwd()
#define model parameters
x=np.linspace(-2,2,1000)
#examples of nonlinear functions
f1=x**2-x-1
f2=x**3-3*np.sin(x)
f3=np.exp(x)-2
f4=1-x**2+np.sin(50/(1+x**2))
fig,axes=plt.subplots(1,4,figsize=(12,3),sharey=True) 
for n,f in enumerate([f1,f2,f3,f4]):
    axes[n].plot(x,f,lw=1.5)
    axes[n].axhline(0,ls=':',color='k')
    axes[n].set_ylim(-5,5)
    axes[n].set_xticks([-2,-1,0,1,2])
    axes[n].set_xlabel(r'$x$',fontsize=18)

axes[0].set_ylabel(r'$f(x)$',fontsize=18) 
titles=[r'$f(x)=x^2-x-1$',r'$f(x)=x^3-3\sin(x)$',r'$f(x)=\exp(x)-2$',
r'$f(x)=\sin\left(50/(1+x^2)\right)+1-x^2$'] 
for n,title in enumerate(titles):
    axes[n].set_title(title)

plt.savefig("example15.png", dpi=100)
plt.show()
plt.close()