Keystrokes for Rotations

This lesson uses a graphing calculator to reflect rotate ordered pairs 180.

Materials- Graphing calculator. (TI-83)

  1. Use the following example to demonstrate to the students the procedure of

rotating ordered pairs 180 on a graphing calculator.

(3 , 1), (3 , 6), (6 , 9), (7 , 7), (7 , 10), (8 , 10), (8 , 6), (8 , 1), and (3 , 1).

  1. Enter the ordered pairs of A and B into L1 and L2 on the calculator.Keystrokes for TI-83

-Press STAT and then ENTER. [If there are numbers already in L1 and L2, clear them.] To clear the lists, highlight upward on the name of the list (L1 or L2) and then press CLEAR and ENTER. Once lists are cleared, enter the x- coordinates into L1 and the y- coordinates of the ordered pairs into L2.

  1. To graph the ordered pairs, make sure all the other graphs are turned off.

Keystrokes for TI-83

-Press Y= on the first row and press CLEAR until all graphs have been

cleared.

  1. The stat plots must be cleared.

Keystrokes for TI-83

-Press 2ND and Y= and then scroll down to number 4 “Plotsoff” and press

ENTER twice until it says “done”.

  1. Graph the ordered pairs.

Keystrokes for TI-83

-Press 2NDand Y=, then press ENTER.

-Scroll over to the “ON” and then press ENTER until the “ON” is highlighted.

-Scroll down to type and choose the 2nd type of graph and then press ENTER until it is the only graph type highlighted.

-Scroll down to the Xlist and enter L1. (Press 2nd and 1)

-Scroll down to the Ylist and enter L2. (Press 2nd and 2)

-Scroll down to Mark and choose the 1st option.

  1. Enter the rotation.

Keystrokes for TI-83

-Press STAT and ENTER.

-Go to L3. [If there are numbers already in L3 and L4, clear them.] To clear the lists, highlight upward on the name of the list (L3 or L4) and then press CLEAR and ENTER.

-To enter the rotation 180 the ordered pairs (x, y) will become (-x, -y).

- Highlight L3 name at the top and press ENTER.

-Press the (-), 2ND, 1, and ENTER.

-Highlight L4 name at the top and press ENTER.

-Press the (-), 2ND, 2, and ENTER.

  1. To see the graph of the rotation.

Keystrokes for TI-83

-Press 2NDand Y= and then scroll down to Plot 2 and press ENTER.

-Scroll over to the “ON” and then press ENTER until the “ON” is highlighted.

-Scroll down to type and choose the 2nd type of graph and then press ENTER until it is the only graph type highlighted.

-Scroll down to the Xlist and enter L3. (Press 2nd and 3)

-Scroll down to the Ylist and enter L4. (Press 2nd and 4)

-Scroll down to Mark and choose the 2nd option.

-Press ZOOM and 9.

8. Assign worksheet on rotations to be done in a similar manner.