Activity #$1$: Small functions $-$individual

This activity is meant to give you more experience writing functions. Name your file small$\_$functions.py and include all of the following parts in one file.

For all parts, include the function named as specified in your submission. Your program does NOT have to include output, however you should test your functions. For example, you might include several function calls and print the results. You may make multiple functions within any one of these problems as long as the main function is named accordingly. Please comment out ALL input $()$statements before submitting.

a$)$Imagine that you have a spherical bead. In other words, a sphere with a cylindrical hole drilled through the middle:

Write a function named parta that will take in as parameters the radius of the sphere and the radius of the hole, and return the volume of the bead.

Note: You will probably want to calculate the volume of a spherical cap