This past term in school, I filled my doodle book with many pen drawings. I had to take this Partial Differential Equations course which I found extremely challenging. This course not only haunted my thoughts, but it also crept its way into my doodles. I actually liked the way the drawing below turned out. Of course, one of the reasons I love math, is because of how artistic it looks!
The first part solves for a wave (u_t=c^2*u_(xx) ) using separation of variables. The second two parts sove for the wave as a function of its initial conditions; on the full line, and on a restricted domain.
I did the wave soon after I experimented with all the colours in my amazing new 14-colour 0.4 MM Stabilo pen set! :D So many amazing colours!