Problem :
If an arc of the unit circle has length
, what is the measure of the central
angle that intercepts that arc?

radians
Problem :
The coordinates of a point on the unit circle are
(0, sin(s)). What is the value of s?
sin(s) = 1, so
s =
+2Πn, where
n is an integer.
Problem :
An angle in standard
position intercepts the unit circle at (x, y). The
arc between (1,0)
and (x, y) has length s. Solve for x and y in terms of s.
x = cos(s), and
y = sin(s)
Problem :
The $x$-coordinate of a point on the unit circle is
. What are the
possible y-coordinates?

and

.
Problem :
Is the equation for the unit circle a function?
No. For a given input (
x-coordinate), there is more than one output (
y-
coordinate). For example, when
x = 0,
y = 1 and -1.