Thoughts from a 21st century educator.

## Using Flex to Create an Algebra Puzzle

I was inspired by an algebra puzzle, done similar to this one, so I decided to build my own.

Algebra puzzle

Also, I've got a quadratic equation version of the same puzzle available here:

## Conic section constructions using Geogebra

The following constructions are all conic sections (as I was teaching this section to my 10th grade students) and are 'quick and dirty' constructions of conic sections. All you need to do in the examples is drag the point C left and right to see the shapes show up.

Parabola:

[geogebra]locus_of_parabola_0.ggb[/geogebra]

Ellipse:

[geogebra]ellipse_construction.ggb[/geogebra]

Hyperbola:

[geogebra]hyperbola_construction.ggb[/geogebra]

## Cubic polynomial with sliders

You can use this applet to show your students how to examine cubic polynomials and determine the effect of changing the 4 coefficients of the equation $$f(x)=ax^3+bx^2+cx+d$$.

[geogebra]cubic_polynomial.ggb[/geogebra]

## Complex multiplication using vectors

In this applet, we can see visually what happens when we multiply two complex numbers (each of which has a length of 1). Vector u, and vector v are multiplied to give vector w.

Try dragging B and C, the endpoints of v and u respectively to try and see what the result of the multiplication of two complex numbers is.

[geogebra]complex_multiplication.ggb[/geogebra]

## Mathematical Equations in Drupal

I'm the maintainer and creator of a filter module for Drupal where users can enter mathematical equations (using MimeTex.cgi created by John Forkosh) and create graphs which are built on the fly (using the JavaScript grapher created by Walter Zorn).

Some examples:

$$x^n+y^n=z^n$$

$$x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}$$

[graph]sin(x)[/graph]

[graph]1/(x^3+1)[/graph]

[graph xmin="-7" xmax="11" ymin="-10" ymax="20"]x^2+4x[/graph]

## Distance formula using Geogebra

This applet shows you how the distance formula varies as you change the position of the points.

Drag A or B and see the effect on the distance formula.

[geogebra]distance_formula.ggb[/geogebra]

Created by David Wees on August 30th, 2007 using GeoGebra - Dynamic Mathematics for Schools

## Countdown game

I've written a series of scripts which:

1. Create a new Countdown puzzle each week.
2. Create a user form so that users can enter their solutions and have them checked.
3. Let the user know whether or not their solution is valid, and if it is, enter them into the database of solvers. It then displays a quick table of the top 10 solutions.

You can try it out here.

## Simple mathematical networks in Flash

This is a very simple script which allows you to create mathematical networks (or graphs). To create a node, click once, after that to connect two nodes, click inside one node, and drag to the other node, and release your mouse. You can also click on a create node, and drag outside to somewhere in the empty space and create a new node.

## JavaScript truth tables

I'm working on a script that allows a user to enter in a logical statement in symbolic form, and then the script creates the truth table for that logic. It doesn't work perfectly yet, but it's an interesting exercise. One of my students asked me if the reason we studied logic was partially because of computers, and I agreed.

Check it out here.

## Flash Compass

This is a simple compass, created in Flash. I'm just intending it as a demonstration tool for one of my classes.