The+Unit+Circle

==The Unit Circle is a circle with a radius of 1 that is centered on the origin. In trigonometry The Unit Circle is used to create reference triangles with x and y values representing the two legs of the triangles.==


 * //Below is a diagram of the Unit Circle. It shows all special angles in both radians and degrees, and displays the x and y values//**
 * //(or legs) of each reference triangle.//**




 * The Trig functions come into play with the reference triangles because** [[image:unitci48.gif align="left"]]


 * Sine is represented by the vertical leg while Cosine is represented by the horizontal leg.**
 * This means that not only does** x^2 + y^2 = 1**, but also** [[image:unitci51.gif]]




 * The following link contains animated images demonstrating how the properties of the sine and cosine graphs come from the infinite right triangles found in the unit circle.**

http://www.humboldt.edu/~dlj1/PreCalculus/Images/CircleScope.htm

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The information and images on this web page can be found at http://www.regentsprep.org/Regents/math/algtrig/ATT5/unitcircle.htm