## Tuesday, October 07, 2008

### Algebra 2: Operations on Complex Numbers

This week, we've been working on adding, subtracting, multiplying, and dividing complex numbers. The students who are good at polynomial operations from algebra 1 love this unit, because it is so easy. But there are many students who never really mastered this in algebra 1, so they are more frustrated, but it is a good chance for them to review and finally get this fundamental algebra skill. Here is an example of the main problem that students have:
(3 + 2i)(4 - 5i)
(3 + 2i) - (4 - 5i)
The number of students who do these two problems the same way, even after focusing on this specific distinction multiple times, is kind of staggering. They are all FOIL happy!

Well, little by little, bit by bit, we'll make progress, as always. And then they'll forget it, and we'll start again. One day it'll hold, I just have to believe.

Here are the files from Monday and Tuesday.

Lesson 3: Adding, Subtracting, and Multiplying Complex Numbers
Lesson 3 Keynote
Keynote Quicktime

Lesson 4: Dividing Complex Numbers
Lesson 4 Keynote
Keynote Quicktime