Sharp EL-9600 - Page 67

Blackline Masters/TRIGONOMETRY USING THE SHARP EL-9600 63
Copyright © 1998, Sharp Electronics Corporation. Permission is granted to photocopy for educational use only.
Activity 1 Verify the half-angle formula
sin ( ) = ± ( ):
1. Press Y= CL to clear Y1 of an old expression. Press ENTER CL to clear
additional expressions.
2. Make sure the calculator is in radian mode by pressing 2ndF SET UP ,
touching B DRG, and double touching 2 Rad. Press 2ndF QUIT to exit the
set-up menu.
3. Enter the sin ( ) for Y1 by pressing sin X/θ/T/n a/b 2 ENTER .
4. Enter the ( ) for Y2 (limiting domain to an interval where sine
is positive) by pressing 2ndF a/b 1 – cos X/θ/T/n ▼ 2
ENTER .
5. Sin ( ) is positive for 0 < x < 2π. Enter this range by pressing WINDOW
0 ENTER 2 2ndF π ENTER 2ndF π ÷ 2 ENTER (–) 2
ENTER 2 ENTER 1 ENTER .
6. Check to see if they result in the same graph by pressing GRAPH .
Sketch what you see in the box below:
GRAPHICAL VERIFICATION OF FORMULAS AND IDENTITIES
3.3
NAME _____________________________________________________ CLASS __________ DATE __________
θ
2
(1 – cos
θ)
2
(1 – cos x)
2
x
2
x
2
√
√
√