Here are links for some notes I have prepared. The notes are maintained in Github Repositories and are open source. This includes the orginial LaTex sources, any code needed to generate graphs, and the original .svg files used for any manually generated graphics.
These notes contain a collection of examples that I consider interesting due to either historical importance, applications, technique, or challenge. They are not necessarily easy examples, but I believe they are all appropriate for an undergraduate level. I've tried my best to properly identify where each example belongs.
These notes are similar to the undergraduate notes, but their level is more appropriate for the graduate level.