22
Arc trigonometric functions, the inverse of trigonomet-
ric functions, are used to determine an angle from ratios
of a right triangle. The combinations of the three sides
are sin
-
1
, cos
-
1
, and tan
-
1
. Their relations are;
Arc Trigonometric Functions
[DEG mode]
(arc sine) Determines an angle based on the ratio
b/a of two sides of a right triangle.
(arc cosine) Determines an angle based on the ratio
c/a for two sides of a right triangle.
(arc tangent) D etermines an angle based on the
ratio a/b for two sides of a right triangle.
<Example>
At what angle should an airplane climb in order
to climb 80 meters in
1
00 meters?
80
100
O per ation
D isplay
θ
= sin
-1
b
a
θ
= cos
-1
c
a
θ
= tan
-1
b
c
c
a
b
θ
DEG
