Back to Baby Math

It's rather funny: the higher up in mathematics you go, you often revisit "duh" topics, usually to illustrate a point. Today, in my diffy q's class, copied from the blackboard verbatim, was written this:

a + x = b
-a + (a + x) = -a + b
(-a + a) + x = -a + b
0 + x = -a + b
x = b - a

ax = b
a^-1(ax) = a^-1b
(a^-1a)x = a^-1b
1x = a^-1b
x = b/a

I was chuckling inside as my professor explained about opposites and inverses and associative properties, etc.

Despite this seemingly easy revisitation to 7th grade math, this course is very difficult. Right now we're learning how to solve systems of nonhomogeneous higher order differential equations. My head is swimming with linear operators, matrix multipliers, LaPlace transforms, and superposition.

Come March 10th, I will fall into a deep sleep for 10 days.