Search results
Results from the WOW.Com Content Network
Point P(x,y) on the circle of unit radius at an obtuse angle θ > π/2 Sine function on unit circle (top) and its graph (bottom) The unit circle centered at the origin in the Euclidean plane is defined by the equation: [2] + = Given an angle θ, there is a unique point P on the unit circle at an anticlockwise angle of θ from the x-axis, and ...
Animation demonstrating how the sine function (in red) is graphed from the y-coordinate (red dot) of a point on the unit circle (in green), at an angle of θ. The cosine (in blue) is the x-coordinate. Using the unit circle definition has the advantage of drawing a graph of sine and cosine functions.
Because PQ has length y 1, OQ length x 1, and OP has length 1 as a radius on the unit circle, sin(t) = y 1 and cos(t) = x 1. Having established these equivalences, take another radius OR from the origin to a point R(−x 1,y 1) on the circle such that the same angle t is formed with the negative arm of the x-axis.
All of the trigonometric functions of the angle θ (theta) can be constructed geometrically in terms of a unit circle centered at O. Sine function on unit circle (top) and its graph (bottom) In this illustration, the six trigonometric functions of an arbitrary angle θ are represented as Cartesian coordinates of points related to the unit circle.
Main page; Contents; Current events; Random article; About Wikipedia; Contact us; Donate
All of the right-angled triangles are similar, i.e. the ratios between their corresponding sides are the same. For sin, cos and tan the unit-length radius forms the hypotenuse of the triangle that defines them. The reciprocal identities arise as ratios of sides in the triangles where this unit line is no longer the hypotenuse.
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
The quantity 206 265 ″ is approximately equal to the number of arcseconds in a circle (1 296 000 ″), divided by 2π, or, the number of arcseconds in 1 radian. The exact formula is = (″) and the above approximation follows when tan X is replaced by X.