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Rational functions – Sharp EL-9900 User Manual

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Advanced Keyboard/ALGEBRA USING THE SHARP EL-9900

Copyright © 2002, Sharp Electronics Corporation. Permission is granted to photocopy for educational use only.

1.

Graph the rational function f(x) = by first pressing Y= CL to clear

the Y1 prompt. Press ENTER CL to clear additional Y prompts.

2.

Enter Y1 = by pressing a/b X/

θ/T/n

– 1 X/

θ/T/n x

2

– 1 .

3.

Graph in the decimal window by pressing ZOOM A (ZOOM) 7 (Dec).

4.

The function consists of two branches separated by the vertical asymptote

(the line x = -1). Look closely at the graph and observe the “hole” in it at

x = 1. Press TRACE and investigate the "hole." Note that the hole will be

seen only when the window is a "friendly" or decimal window.

5.

Notice that there are no x-intercepts for the graph. The y-intercept can

easily be found at x = 0, y = 1 by pressing 2ndF CALC and 6 (Y_Incpt).

6.

Observe that the line y = 0 is very likely a horizontal asymptote of f(x).

RATIONAL FUNCTIONS

(x – 1)

(x

2

– 1)

(x – 1)

(x

2

– 1)