## Tuesday, 18 December 2012

### Fractional Integrals = Blow Your Mind

The following is less of a resource for education, and more of a "cool math fact".

Given a function f, a lower value a, and a value n representing the number of integrations we want to do, we can calculate the value of f -n using a single integral of the following form:

## Saturday, 15 December 2012

### Metaconcepts in Physics

There are four major classes of phenomena that are encountered in the physical sciences:
• Particles
• Waves
• Flow and
• Fields
Understanding the general properties of these phenomena enable you to understand a large variety of events in the natural world.

## Friday, 14 December 2012

### Iodine Clock Reaction Kinetics

The following is a quick description of a reaction I developed and refined over the period of three years. It is an adaptation of this experiment.
The Berocca makes it quicker to accurately prepare solutions of Vitamin C, and the distilled water removes any variability from the hardness of the tap water.

### SageMath and 3D Graphics

As mentioned in an earlier post, Sage Maths is a high-level mathematical system that combines a large variety of open-source (free) software into one powerful bundle.
In the classroom, one of the most exciting features is it's interactive 3D plots.

### Network Graphic Objects in SageMath

See here for how to install SageMath:
http://australianteacher.blogspot.com.au/2012/12/installing-sage-mathematics-on-windows.html

At the end of this year, my school set our Year 10's some network theory as their last topic for assessment. I quickly needed a way to generate weighted networks for worksheets. Yes, hand-drawn would have worked, but like all things, once you put the effort into making a program, it's only a couple of edits and clicks to make multiple diagrams. Plus this way, I can also use the same SageMath worksheet to generate the answers as well.

### Introduction:

Sage maths is an open-source mathematics package that rivals Mathmatica in function and power.

From it's website (sagemath.org):
"Sage is built out of nearly 100 open-source packages and features a unified interface. Sage can be used to study elementary and advanced, pure and applied mathematics. This includes a huge range of mathematics, including basic algebra, calculus, elementary to very advanced number theory, cryptography, numerical computation, commutative algebra, group theory, combinatorics, graph theory, exact linear algebra and much more. It combines various software packages and seamlessly integrates their functionality into a common experience. It is well-suited for education and research."

This article describes how to install and run sage math on a Microsoft computer.

### Install Emulator and Image

Sage math is built on a lot of packages, unfortunately most of which are only available on Linux. Efforts are underway to port sage math to windows, but in the meantime, you will want to run sage math inside an emulator.

2. Download the current sage math virtualbox image from the University of Sydney mirror. (Grab the latest file that ends with .ova).
3. Open the VirtualBox program, and import the sage math image by clicking 'File', then 'Import Appliance'.
4. Once VirtualBox finishes importing the image, you can start sage math by double-clicking on Sage-5.x in VirtualBox. If sage math asks for a user and a password, type admin for user and sage for password (Or depending on the release, sage and sage for both password and username).
Sage math runs a server and a Web-based graphical user interface. You can use the interface from within VirtualBox, but you can't copy-paste to other programs. The next section shows how to access the interface from your machine's normal web browser.

As mentioned, sage math runs as a server that you can access by pointing your normal browser at localhost:8000 (or 127.0.0.1:8000).
However, when I first wrote this article, it was intended for fellow Education Queensland teachers who were using government-supplied laptops, which ran a piece of software called BlueCoat Proxy. This program already claimed port 8000, conflicting with Sage Math rather badly.
It is possible to reset the image's port address, this involves changing some settings in the VirtualBox software.

1. In the running Sage-x.x window, click on the menu "Devices", then click on "Network Adaptors", then click on the button at the bottom called "Port Forwarding".
2. There is an entry under Host Port with the number 8000. Change that to 8080. Leave the Guest Port number for that line as 8000. CLick on "OK" twice.
3. This should take you back to the sage math image (which looks like a wall of text). In the menu "Machine", click on "ACPI Shutdown" to shut the sage math image down.

### Running the Software

You will want to open your desktop browser to 127.0.0.1:8080. If it asks you to log in, you will need to use admin for the username and sage for the password. (Or sometimes sage and sage depending on who built the image).

Running from the desktop browser means that you will be able to copy equations from Sage and place them in Microsoft Office 2010+, as well as images.

Sage math is now installed and correctly configured, and ready to run. A good place to start learning sage math is the tutorial available at:
http://sagemath.org/doc/tutorial/tour.html
Sage is based on a computer language called Python that is wonderfully easy to learn. Make sure to activate the "typeset" option box once you create a new page to get pretty equations.

### What is geometry useful for any way?

Hear this question a lot?

The following are links to some old metalworking (and woodworking) books which show that metalworking and woodworking engineers of the past really knew their stuff.

http://archive.org/details/metalplateworkit00millrich
http://archive.org/details/mechanicsgeometr00ridd
http://archive.org/details/tinsheetironcopp00bliniala