Controlling the graph:
 

• To rotate the graph, click on the image and drag.  To stop the rotation, click once in the box containing the graph.
• To zoom out, click the "rocket ship" button.
• To zoom in, first rotate the graph so that you are looking down on it from above.  Click the "knife" button and then click and drag over the portion of the image that you would like to enlarge.  When you release the mouse button, the graph will zoom in.
• To change the formula for the function, click and drag over the expression (not including the z ).  Backspace to delete the entire expression, and then type your new expression.  Here are some additional hints:
• Use the ^ key for powers.
• Use * to indicate multiplication.  (This is essential; however, you will not see the asterisk in your expression.)
• Use "sqrt" for square root. (This will be changed to the square root symbol automatically.)
• As soon as you type a left parenthesis, the matching right parenthesis will be supplied automatically.
• The size of the cursor (the vertical line) will help you figure out whether you are on the main line or on the exponent line.
• You may have to point with the mouse and click, to move from exponent to main line and vice versa.
• If, after entering a new formula, the page says "Cannot draw this graph," try clicking in the space where the graph should appear.  If your formula makes sense, this should cause the graph to be drawn.
• If your mathematics gets hopelessly messed up, simply click RELOAD (or REFRESH) on your browser, and try again.

 
 Have fun!!