6
Advanced Keyboard/TRIGONOMETRY USING THE SHARP EL-9900
Copyright © 2002, Sharp Electronics Corporation.  Permission is granted to photocopy for educational use only.
Investigate the change in a trigonometric function by multiplying
the argument θ by 2.
1. Press  Y=    CL  to access and clear Y1 of an old expression.
2. Make sure the calculator is in radian mode by pressing  2ndF    SET UP  , 
B (DRG) and   2    (Rad).  Press  2ndF    QUIT  to exit the menu.
3. Now, enter sin x for Y1 by pressing  sin    X/θ/T/n ENTER  and the sin (2x)
for Y2 by pressing  CL    sin    
(
2    X/θ/T/n
)
ENTER  . 
4. Set your viewing window by pressing  ZOOM    E   (TRIG) and   1 (sin x).
Note the change in the second graph versus the first graph.  Engage the 
trace to show the period has changed from 2π to π.
Investigate the change in a trigonometric function by subtracting    
to the argument θ.
1. Press   Y=    ▼ CL   and enter Y= sin (X - 3π/2) for Y2 by pressing
sin     (     X/θ/T/n –      3    2ndF    π ÷ 2 )     ENTER   .
2. Press   GRAPH   to view the graphs.  Observe and note the changes in sin x
when you change the phase shift.
PERIOD AND PHASE SHIFT
3π
2