I have an assignment where I am trying to replicate the following subplots

I successfully replicated the three non-polar plots, but I cannot figure out how to set the fourth plot to polar. Here is what I have so far with my code, only including code relevant to the polar plot.

```
nmax=101 # choose a high number to "smooth out" lines in plots
x = np.linspace(0,20,nmax) # create an array x
y = np.exp(-x/4)*np.sin(x) # y for the top two subplots
fig, axs = plt.subplots(2, 2)
# bottom right subplot controls
axs[1, 1].polar(x, y)
```

This will give the error, `AttributeError: 'AxesSubplot' object has no attribute 'polar'`

. How would I set the subplot to polar?

Thank you all in advance!