Unit Circle

A unit circle is a circle that has a radius of one unit.

Certain trigonometric functions are simpler in unit circles. For example the coordinates of a point on a circle of radius r are given by
x = r cos(t)
y = r sin(t)
If the radius is one, as in a unit circle then the coordinates simplfy to
x = cos(t)
y = sin(t)

Pages referring to 'unit-circle'

A circle can be defined as the locus of all points that satisfy an equation derived from Trigonometry. Interactive coordinate geometry applet.