Algebra Xpresser Lab #1

INTRODUCTION:

You will be using a program called Algebra Xpresser. This program will allow us to graph the linear equations we have been exploring in the classroom using the graphing calculators. The graphs here will be a bit more easy to see and much more colorful.

GETTING STARTED WITH ALGEBRA XPRESSER:

Go to the APPLE and select ALGEBRA XPRESSER.

You should see a white screen with a tool bar to the right. You will see that is selected, or in other words highlighted. This is where we will type in the equations we want to graph. Make sure your CAPS LOCK is off.

Now, you will type in y = x + 2. To look at a graph of this linear equation, you will go to the tool bar on the right and select the tool on the bottom that shows a picture of a graph.

You should see a graph of the linear equation y = x + 2. Notice that you have some new tools on the right below your normal tools. These tools will create tic marks, a grid, and numbers on your coordinate plane. Highlight each of those tools by clicking on them with your arrow. Now it should be easy to identify some ordered pairs on your graph.

ZOOMING IN:

If you want to get a closer look at some portion of your graph, you will have to zoom. You do this by creating a box around the area you want to see up close. To create the box, click on the upper right or left hand side of the area you want to see up close and do not let go of the mouse. Drag the mouse until you have a box around that area. When you let go, you will see your graph zoomed in. You should be able to see some definite ordered pairs.

RESIZING THE WINDOW:

If you want to resize the window to get back to your "standard" window (-10 to +10 on both axes), you will need to select the third tool down on your tool bar. It looks like a smaller graph with arrows on both sides. When you select this, you will get a smaller version of your graph. By clicking on the house button, you will get back to your original standard window. Your window should now be resized.

TRACING:

If you want to trace your graph to identify ordered pairs, you must click on the "+" sign in the upper right hand corner of your screen. You will see a box open up with x and y. As you move your mouse over the screen, it will tell you the ordered pair at each location. It is very tricky to use the trace function here because you will have to be "precisely" on your line in order to identify those solutions of your equation. It is much easier to read the points that are on your line by finding its ordered pair looking at the x and y axis.

PROJECT ONE:
Use the tool bar to select the tool. Clear out any equations that are already there. You are going to be entering more than one equation at a time. To do this you will go to a new line and enter the word "or" before the next equation.

ENTER y = x + 3
GRAPH What is the color of the line? _______

What is the ordered pair of the point that touches the x-axis? _______

What is the ordered pair of the point that touches the y-axis? _______

Now below that equation,
ENTER or y = x + 5
GRAPH What is the color of that line? _______

What is the ordered pair of the point that touches the x-axis?_______

What is the ordered pair of the point that touches the y-axis? _______

How are the graphs alike? Compare below:

Can you predict what y = x - 3 will look like? Can you predict what the ordered pair of the point that touches the x-axis will be? Can you predict what the ordered pair of the point that touches the y-axis? Answer below.

Graph y = x - 3 to see if you were right. Sketch a picture of what y = x - 5 will look like based on that information.

PROJECT TWO:
Clear out your equations from the screen.

ENTER y = 3
GRAPH What is the color of the line? _______

What is the ordered pair of the point on the y-axis? _______

ENTER or y = -5
What is the color of the line? _______

What is the ordered pair of the point on the y-axis? _______

Predict what y = 8 will look like and respond below. Check and see if you are right.

PROJECT THREE:

ENTER x = 3
GRAPH What is the color of the line? _______

What is the ordered pair of the point on the x-axis? _______

ENTER x = -5
GRAPH What is the color of the line? _______

What is the ordered pair of the point on the x-axis? _______

Predict what x = 2 will look like below with a sketch. What point will be on the x-axis?

Can you guess what the graph of y = 0 will look like? x = 0? Sketch them below and then graph them one at a time to see the results.

PROJECT FOUR:
Clear out your screen. Graph the following equations one at a time. Keep the previous equations up there noting the colors of the lines and comparing the beginning graph with each new addition.

GRAPH y = x What is the color of the line? _______
GRAPH or y = 2x What is the color of the line? _______
GRAPH or y = 3x What is the color of the line? _______
GRAPH or y = 5x What is the color of the line? _______
GRAPH or y = -2x What is the color of the line? _______

What affect did the increasing number have on your original line?

What affect did the -2 have on your original line? Predict what y = -4x will look like by sketching below:

PROJECT FIVE:
Clear out your screen. Graph the following equations one at a time. Keep the previous equations up there noting the colors of the lines and comparing the beginning graph with each new addition.

GRAPH y = 2x What is the color of the line? _______
GRAPH or y = 2x + 1 What is the color of the line? _______
GRAPH or y = 2x + 5 What is the color of the line? _______
GRAPH or y = 2x - 3 What is the color of the line? _______

What is the ordered pair of the point that the line goes through on the y - axis for:

y = 2x? ______

y = 2x + 1? ______

y = 2x + 5? ______

y = 2x - 3? ______

What affect does adding or subtracting a number have on your original graph? Can you predict what the graph of y = 2x - 6 will look like? What will be ordered pair of the point that the line goes through on the y-axis?