Sharp EL-W516B User Manual
Calculator Activity
TRIGONOMETRIC FUNCTIONS
OBJECTIVE: To find the distance between points by using trigonometric functions.
The law of sines and the law of cosines can help determine the sides and
angles of triangles. The law of sines is as follows
sin
sin
sin
c
b
a
.
The law of cosines is as follows
cos
2
2
2
2
ab
b
a
c
.
1. Using the law of sines find the length of side a given
4
,
53
,
37
b
.
STEP 1: Set the angular units to degrees by pressing
.
STEP 2: Multiply 4 by
)
37
sin(
by pressing
.
STEP 3: Divide by
)
53
sin(
by pressing
.
2. Using the law of cosines fine the length of c given
radians
b
a
2
,
12
,
5
.
STEP 1: Set the angular units to radians by pressing
.
STEP 2: Add
2
5
and
2
12
by pressing
.
STEP 3: Subtract
)
2
cos(
12
5
2
by pressing
.
STEP 4: Take the square root by pressing
.
Note: Tangent can be used in a similar manner as sine as cosine.
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