Recently in Pre-Calc I made a unit circle. I use this unit circle by knowing that in order to get a the radius of a number, for example lets use 60 degrees. I take the degree times 180, then divided by pi. which is, pie over 3. In order to find the degrees of a radius like pie over 3, i would do that radius times pi, divided by 180. We also used 30-60-90, and 45-45-90 degree triangles to find the degrees of the spots around the circle. Then, we found the coordinates. So if i were to be asked to find the sine of 120, i would look at the y coordinate and say that sine of 120 is the square root of three over two. in order to find the cosine of 120 i would look at the x coordinate and say that the cosine of 120 is negative 1 over 2. if i were asked to find the tangent of 120 i would take the sine of 120 divided by the cosine of 120 in order to get my answer. My answer would be 2pi/3.
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