## Friday, November 6, 2009

### Calculator Customization Using Transformations (Post #1)

From the Geometry class blog. This project is pretty popular, and has been making the rounds with TI trainers for a while.

This first post describes how to get the picture into the calculator. The next post will talk about transforming the picture, and using the final drawing as a start-up screen in a TI-83 or 84.

Overview: Put a drawing in the calculator, do some transformations on it, add your name, and use it as the start up screen in your calculator, like this:

Part 1: Create a Design:
1. On graph paper, create a simple design that can be entirely drawn without picking up your pencil.
2. You may want to trace a cookie cutter or a stencil.
3. Draw axes on the paper in a sensible place, so that all your points are in Quadrant I. (x and y both positive)
4. Label points on the drawing with their coordinates. Eventually, the calculator will be connecting these points with straight line segments, so be smart about it. Curvy sections will need more points if you want them to look smooth. Here is an example:

Part 2: Calculator
1. STAT, Edit. Clear all old data in any list. (Highlight the title of the list, and press CLEAR, Enter.)
2. Enter the x-coordinates of all points in L1 and the corresponding y-coordinates in L2. Enter them in the order you want them connected.
3. If the design is a closed figure, you have to enter the coordinates of the starting point again as the last point.
4. 2nd, Y= (STAT PLOT). Press Enter on Plot 1, and set it up as below:

5.  Press WINDOW and set both x and y from -15 to 15. You may have to adjust this later.
6. Press 2nd FORMAT and highlight "Axes Off".
7. Press GRAPH to hopefully see your picture.

The next step is to use L3, L4, etc to draw transformations of your graph. I'll pick it up from here in the next post.