6.4 Radians, Arc Length, and Angular Speed

Find points on the unit circle determined by real numbers.

Convert between radian measure and degree measure; find coterminal, complementary, and supplementary angles.

Find the length of an arc of a circle; find the measure of a central angle of a circle.

Convert between linear speed and angular speed.
Another useful unit of angle measure is called a radian. To introduce radian measure, we use a circle centered at the origin with a radius of length 1. Such a circle is called a unit circle. Its equation is $x{\text{\hspace{0.05em}}}^{2}+y{\text{\hspace{0.05em}}}^{2}=1$.
Distances on the Unit Circle
The circumference ...
Get Algebra and Trigonometry, 5th Edition now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.