Evaluate Polar Expressions on the TI-83 Plus
You can use the TI-83 Plus graphing calculator to evaluate polar expressions that you have entered and graphed. To evaluate polar equations at a specified value of
follow these steps:
Graph the equation in a viewing window that contains the specified value of
To get a viewing window containing the specified value of
that value must be between
Set the Format menu to ExprOn and CoordOn.
Press [2nd][TRACE] to access the Calculate menu.
Press  to select the value option.
Enter the specified value of
To do so, use the keypad to enter the value of
If you make a mistake when entering your number, press [CLEAR] and re-enter the number.
After you press [ENTER], the first highlighted polar equation in the Y= editor appears at the top of the screen, the cursor appears on the graph of that equation at the specified value of
and the coordinates of the cursor appear at the bottom of the screen.
to see the value of the other graphed polar equations at your specified value of
Each time you press
the name of the polar equation being evaluated appears at the top of the screen and the coordinates of the cursor location appear at the bottom of the screen.
If you’re planning to evaluate polar equations at several specified values of
consider constructing a user-defined table.