?
4. How do I graph ?
Press Y= to open the graph editor, and set Y1 equal to x and Y2 equal to -x. Press ZOOM , select ZSTANDARD, and press ENTER . Notice that even though y = x and y = -x are supposed to be perpendicular lines, they don't look perpendicular in our graph! This is because our graph window is wider than it is high. Hence, we usually look at a graph which is distorted and elongated in the horizontal direction! To correct this distortion, press ZOOM , select ZSQUARE, and press ENTER . This will force the calculator to use the same scale on the x and y axes.
5. How do I graph 
?
Press Y= to open the graph editor, and set Y3 equal to 
and Y4 equal to 
. To deselect Y1 and Y2, use
the arrow keys to move the cursor over the equal signs next to these symbols
and press ENTER . Now press ZOOM , select ZSTANDARD,
and press ENTER . Notice that the graph which should look like a
circle is distorted. To correct this, press ZOOM , select ZSQUARE,
and press ENTER . The circle now looks better, but notice that the
top and bottom halves are not connected to the x-axis. This occurs because
x = -2 and x = 2 were not among the points plotted by the calculator to
generate this graph. To correct this situation, press ZOOM , select
ZDECIMAL, and press ENTER .
6. How do I graph y = |x|?
Press Y= to open the graph editor, and set Y1 equal to ABS x (press 2nd --> x-1 on a TI-80 or 82, and look in the NUM submenu of MATH on the TI-83). Clear or deselect all other functions. Press ZOOM , select ZSTANDARD, and press ENTER . We will now generate a table of values for this function. To do this, press TblSet ( 2nd --> WINDOW ). Clear the current value for TBLMIN and set it to a convenient starting point such as -3. Now set the increment ( TBL ) to either 1 or some other desired value. Press TABLE ( 2nd --> GRAPH ), and you should see the desired table. Notice that you can easily use the arrow keys to scroll forward or backward in the table.
