4.7. What to Remember from Lesson 3

This has been a whirlwind pass through lots of mathematics from you past. I’d like you to remember that functions are nothing more than little machines for taking a variable and turning it into a value. The world seems to be astonishingly well described by models made up of functions! Some of them are easy and some of them are complex. Only some very simple manipulations will be required. See the Fairness Doctrine of Algebra!

I’ll ask you to “read” functions sometimes, but I promise: only when they are simple and only when there’s physics insight to be gained from that. Otherwise, we’ll be content to read graphs to “evaluate” functions because, well, it’s the same thing.

4.7.1. Powers of 10.

That will be an important tool since we’re talking about the largest things in the universe and also the smallest things in the universe.

4.7.2. Geometry

There are some simple equations, areas, and circumferences of geometrical objects that I’ll need you to remember: line, circle, triangle.

4.7.3. The rest

The rest of the items in Lesson 3 are there for you to refer to when we touch on some science stories that need them.