Sharp EL-9600 User Manual page 44

Using Blackline Master 8.3
The problems discussed in the Calculator Operations section are presented on
Blackline Masters 8.1 and 8.2. Problem 1 on Blackline Master 8.3 involves the
angles of elevation of the sun. Remind students that the angle of elevation is
the angle, measured upward from the horizontal, to the line of sight of an object.
The Graphic Solver provides an added exploration when finding the solution to
this problem. In the variable list for the Law of Sines, enter 60 for A, 50 for X,
and 40 for Y. Solve for B using BEGIN= 0 and END= 180 to obtain B = 43.85°.
Notice, however, that two intersections are visible. Press 2ndF
the Graphic Solver will find the other intersection at B =136.15°. Have students
discuss why this is not a possible value for B. Once B is found,
90 – = 180 – (60 + 43.85) = 76.15 yielding
For Discussion
Students can discuss how to retrieve and rename the stored equations for the
Law of Sines and the Law of Cosines.
Additional Problems
Problems 1-3 refer to the following situation:
A tower on the top of a hill is 40 feet tall.
The angle of elevation from point B at the
base of the hill to the top of the tower (point
T) is 45°. The angle of elevation from
point A, 800 feet from the base of the hill, to
point T is 22°.
1. Find the distance d from point A to the top of the tower.
2. A cable is stretched taunt between points B and T. Find the length of
the cable.
3. Find the height h of the hill.
4. The angle of elevation of the top of a flagpole
from point A is 22°. The angle of depression of
the top of the flagpole from a helicopter hovering
1200 feet above point A is 25°. Find the distance
from the helicopter to the top of the flagpole.
40 Law of Sines and Law of Cosines/TRIGONOMETRY USING THE SHARP EL-9600
= 13.85°.
d
22°
A
800 ft
helicopter
1200 ft
A
CALC and
T
40 ft
h
B 45°
)
25°
R
22°
)