Beginning Graphing Hints for TI's

I am using a TI-83.  There is little difference between the TI-83plus, TI-83, and the TI-82 for graphing. For shading with the TI-82, use the SHADE function.

 Page 7 gives instructions for graphing lines.   Additional instructions are in Appendix B.

Example 1
Try graphing the equation y = (1/2)x, y = x, y = 4x on the same screen.

Press GRAPH after entering equations.

Notice how each graph is steeping than the previous one.  This is the slope of the line.  Experiment with different slopes. i.e.  y = -2x, y = -(1/2)x

y = mx where m is the slope of the line

Press the  Y =  key (noted by a red dot)

Notice the = signs are highlighted.  Highlighting the = signs turns the equations on which allows you to see their graphs when GRAPH is pressed.

I pressed TRACE after pressing GRAPH.  Use the arrow keys to move left and right along Y1 (equation 1) .  Use the arrows keys (up and down) to scroll between each equation.

If you don't see the expression in the upper left-hand corner, press 2nd FORMAT, (above ZOOM key) and make sure everything is highlighted on the left hand side.
If you don't see the coordinates (x =, y = ) following above instructions.

 Let's look at the y-intercept            y = mx + b where m = slope and b = y-intercept
Graph the equations y = x and y = x +5

Notice the y-intercept for Y1 is (0,0)

Notice the y-intercept for Y2 is (0,5)

You may need to clear old equations by moving the cursor to the desired line in the "Y =" screen and press CLEAR.

Remember to press TRACE to see equations and coordinates.