Example Activity – Polynomial Root Finder

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Example Activity – Polynomial Root Finder

Use this activity to learn the basics of the App.

A golfer hits a golf ball from a tee at the bottom of a hill.
You can describe the hill by y(x) =0.8x.
The ball follows the path y(x) = -x2 + 12x.

If the golfer is standing at the tee (0, 0) and hits the ball, where does the ball hit the ground on the hill?

First, equate the two equations:

x2 + 12x = 0.8x

-x2 + 11.2x = 0

The roots of the resulting polynomial will give the intersection points of the ball path and the hill.

Press Œ to display a list of applications on your calculator.

Select PlySmlt2.

The ABOUT screen displays.

Press any key to continue.

The MAIN MENU displays.

Select POLYNOMIAL ROOT FINDER.

Select the degree of the polynomial as ORDER 2.

Press NEXT(s). Enter the coefficients of -x2+11.2x=0.

Note: You can also change the operation in the polynomial as needed.

Select SOLVE (s) to calculate and display the roots. Two answers are displayed in fraction form as shown. Press [Fe3 4D] (s) to toggle to the decimal results:
x1 = 0 and x2 = 56/5

Note: If you exit the application, graph the two functions, and find their intersection (press y / and then select Intersect), you can see that the ball starts at (0, 0) and hits the hill at (11.2, 8.96).