import matplotlib.pyplot as plt
import numpy as np

from mpl_toolkits.axes_grid1.inset_locator import zoomed_inset_axes, mark_inset

xs = np.linspace(-7, 7, 10001)
sin_ys = np.sin(xs)

f, ax = plt.subplots()

ax.plot(xs,sin_ys, label="$\\sin(x)$")
ax.plot(xs, xs, label="$f(x)=x$")
ax.set_xlim(-7,7)
ax.set_ylim(-1.6,1.6)
ax.legend(loc=2)

axins = zoomed_inset_axes(ax,3.1,loc=4)
axins.plot(xs,sin_ys)
axins.plot(xs,xs)
axins.set_xlim(-0.6,0.6)
axins.set_ylim(-0.5,0.5)

mark_inset(ax, axins, loc1=3, loc2=2, fc="0.95", ec="0.7")

plt.xticks(visible=False)
plt.yticks(visible=False)

plt.savefig("Small-angle approximation for sine function.svg")