Here’s one of the things about complex numbers which is easier if you know it so well you don’t have to think about it: the formula for sin x. Nice and easy. Assumes you already know Euler’s formula, eix = cos x + i sin x.
Category: Math
A clear explanation of the epsilon-delta definition of a limit
Assuming you know the basics (tan=sin/cos, etc), here are strategies and examples for proving simple trig identities.
What are fraction exponents? Why is x⅓=∛x? Here’s an explanation.
You probably already know that 20=1. In fact any number to the power of 0 is one. But why?
Gauss was just ten years old when he discovered how to quickly add up a long series of numbers. Here I tell the story of how he outwitted his teacher and I also walk you through a mathematical proof.
A lively presentation of how to solve a two different word problems involving motion, using distance = rate * time. The text is a little small so click the “full screen” option to really see it. (I’ll redo this eventually — still learning ins and outs of Zoom!)
Lots of calculus students learn to solve differential equations without understanding what they really mean. Here’s a simple example of a differential equation so you can see how it works.
Categories
Saved by a Word Problem
A lively and amusing example of using “guess and check” to write an equation to solve a word problem which got me out of a jam. Just like we teachers always tell you might happen someday: this really happened to me!