HP 39gs Graphing “Build Your Own” menu keys, Example: plotting a circle

“Build Your Own” menu keys

KeyMeaning

Puts the highlighted independent value (X, T, θ, or N) into the edit

line. Pressing replaces this variable with its current value.

Inserts a zero value at the position of the highlight. Replace a zero by typing the number you want

and pressing .

Sorts the independent variable values into ascending or descending order. Press and select the ascending or descending option from the menu, and press .

Toggles between two character sizes.

Displays the defining function expression for the highlighted column.

	Deletes the highlighted row.
CLEAR	Clears all data from the table.

Example: plotting a circle

Plot the circle, x 2+ y 2 = 9. First rearrange it to read

y= ±9 – x2 .

To plot both the positive and negative y values, you need to define two equations as follows:

y = 9 – x2 and y = –9 – x2

2-20 Aplets and their views