How to Enter Polar Equations on the TI-83 Plus

By C. C. Edwards

The TI-83 Plus graphing calculator can handle up to six polar equations, r1 through r6. To enter polar equations in the calculator, follow these steps:

  1. Press [MODE] and put the calculator in Polar mode.

    To highlight an item in the Mode menu, use the

    Arrow buttons on a graphing calculator.

    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.

    The available modes on a TI-83 calculator

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

  3. Enter the definition of the polar equation rn, n being an integer between 1 and 6.

    To erase an entry that appears after rn, use the

    The up, down, right and left keys on the TI-83 Plus

    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

    The angle theta.

    Press

    Several independent variables: x, t, and n

    to enter

    Theta

    in the definition of your polar equation. This key was used to enter equations r1, r2, and r3.

    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 r4 is defined in this manner. To paste a polar equation name into the equation you’re entering in the Y= editor, press

    Keys you have to press to paste a polar equation to your current equation.

    and then press the number key for the name of the polar equation you want to paste into the definition.

    Results of a polar equation on the TI-83 Plus