EXAMPLE 1
Evaluate trigonometric functions given a point
Let
(–4, 3)
be a point on the terminal side of an angle
θ
in standard position. Evaluate the six trigonometric
functions of
θ
.
SOLUTION
Use the Pythagorean theorem to find the value of
r
.
x
2
+
y
2
√
r
=
(
–
4)
2
+ 3
2
√
=
=
25
√
= 5