Sharp EL-9900 Manual page 5

EVALUATING TRIGONOMETRIC FUNCTIONS
Steps for evaluating sec (
+ –
1. Press
×
÷
2. Press 2ndF
change it to degree mode. Press 2ndF QUIT to exit the menu.
3. Enter and evaluate the expression by pressing MATH
0 9 (sec) 2ndF
pressing ENTER .
Steps for approximating tan 20° graphically
1. Press Y= and press CL to remove an old expression for Y1.
2. Press 2ndF
change it. Press 2ndF
3. Enter the function tan x for Y1 by pressing tan
4. Instead of graphing the function in the default viewing window for tangent,
press WINDOW adjust the Xmin and Xmax to 10° and 30° (value of interest
± 10° ) respectively to start out closer to the value of interest. Set the Xscl =
1. Press ZOOM
5. Now, engage the trace by pressing TRACE . Notice the tracer appears at
x = 20° since it is the middle of the x values. The approximate for tan 20°
is .36397.
Advanced Keyboard/TRIGONOMETRY USING THE SHARP EL-9900
Copyright © 2002, Sharp Electronics Corporation. Permission is granted to photocopy for educational use only.
π
) directly in degree mode
4
to enter computation mode.
SET UP to verify the calculator is in degree mode. If it is not,
π
a/b 4
SET UP to verify the calculator is in degree mode. If it is not,
QUIT to exit the menu.
A (ZOOM) and 1
MATH E (ANGLE) 4
X/θ/T/n .
(Auto) to view the graph.
3
A (CALC)
(r) and