(I am amazed that list of useful symbols at the top of the page doesn't include pi!)
tau = 2 pi, the measure of a full circle. There are those who argue that tau would be a better choice than pi, but I haven't found that their arguments hold much water. For every calculation it simplifies, it makes another more complex.
exactly! hence my suggestion of a dual system, or at least using tau for angles.
The backtrack quote?
Yes, your school is wise not to appoint me to do anything. I am a difficult employee. I have difficulty relating to younger people. Some are intimidated and call me sir, this is annoying. Others call me gramps, which makes me violent. Others try to mug me which also makes me violent.
And yet, you wonder why no school has hired you?
The Complete Idiot's Guide To calculus: Even if you aren't a complete idiot, this book is absolutely brilliant, period.