21
The angle from a point
1
5 meters from
a building to the highest floor of the
building is 45
°
. How tall is the building?
Trigonometric Functions
[DEG mode]
V
A P P L IC AT IO N S:
Trigonometric functions are useful in mathematics and various engineering
calculations. They are often used in astronomical obser vations, civil engi-
neering and in calculations involving electrical circuits, as well as in calcula-
tions for physics such as parabolic motion and wave motion.
C alculates the sine of an angle.
C alculates the cosine of an angle.
C alculates the tangent of an angle.
<Example>
45
15
iew point
1
5
O per ation
D isplay
sin
θ
=
b
a
tan
θ
=
b
c
cos
θ
=
c
a
a
c
b
θ
DEG
Trigonometric functions determine the ratio of three sides
of a right triangle. The combinations of the three sides are
sin, cos, and tan. Their relations are: