Sharp EL-9900 - Manual (Page 132)

17
Advanced Keyboard/TRIGONOMETRY USING THE SHARP EL-9900
Copyright © 2002, Sharp Electronics Corporation. Permission is granted to photocopy for educational use only.
A lawn sprinkler is set so that the region of the lawn that is watered is
approximately a sector of a circle of radius 6 feet. If the central angle of the
sector is radians, find the area of the region that is watered by the sprinkler.
1. Set the calculator to radian mode by pressing 2ndF SET UP
B (DRG) and 2 (Rad). Press 2ndF QUIT to exit the set
up screen.
2. Access the SOLVER by pressing 2ndF SOLVER . Press CL to delete
any equation that appears on the screen.
3. Type in the equation A= R 2 θ by pressing ALPHA A ALPHA = 1
a/b 2 ALPHA R x 2 ALPHA
θ .
4. Use the Equation solver by pressing 2ndF SOLVER A (METHOD)
and 1 (Equation). Press ENTER and see the list of variables.
5. Use
▼ to place the cursor over R, type in 6, and press ENTER . Type in θ
by pressing 2ndF
π ÷ 5 ENTER . Press ▲ twice to place the cursor
on the A variable. Press 2ndF EXE to find the area in square feet.
6. Use the Newton solver by pressing 2ndF SOLVER A (METHOD) and
2 (Newton). Reset A to 0 to start the problem from the beginning.
The values of R and O are correct for this problem, so use
▲ to place
the cursor over the A variable and press 2ndF EXE to view the Newton
solver screen.
7. Since area is never negative, you could set START = 0. Leave the STEP size
as .001 and remember that you should change it to a slightly larger value if
an error message results. Press 2ndF EXE to find the area in square feet.
AREA OF A CIRCULAR SECTOR
π
5
1
2
▼
Ч
+ –
ч