By the definition of the trigonometric functions,
 |  |  |
(1)
|
 |  |  |
(2)
|
 |  |  |
(3)
|
 |  |  |
(4)
|
 |  |  |
(5)
|
 |  |  |
(6)
|
Trigonometry Angles--0
See also
Trigonometry Angles, TrigonometryExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Trigonometry Angles--0." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/TrigonometryAngles0.html