How to Enter Polar Equations on the TI83 Plus
The TI83 Plus graphing calculator can handle up to six polar equations, r_{1} through r_{6}. To enter polar equations in the calculator, follow these steps:

Press [MODE] and put the calculator in Polar mode.
To highlight an item in the Mode menu, use the
keys to place the cursor on the item, and then press [ENTER]. Highlight Pol in the fourth line to put the calculator in Polar mode.

Press [Y=] to access the Y= editor.

Enter the definition of the polar equation r_{n}, n being an integer between 1 and 6.
To erase an entry that appears after r_{n}, use the
keys to place the cursor to the right of the equal sign and press [CLEAR]. Then enter your definition for the new polar equation.
When you’re defining polar equations, the only symbol the calculator allows for the independent variable is the angle
Press
to enter
in the definition of your polar equation. This key was used to enter equations r_{1}, r_{2}, and r_{3}.
When you enter a polar equation in the Y= editor, as a timesaver you can reference another polar equation in the definition you’re entering. For example, equation r_{4} is defined in this manner. To paste a polar equation name into the equation you’re entering in the Y= editor, press
and then press the number key for the name of the polar equation you want to paste into the definition.