The Unit Circle
THE UNIT CIRCLE

The order pairs in this picture represent Sin and Cos. You can tell which one is which by remembering that it goes alphabetically (Cos, Sin). There are two very similar unit circles below. Both have the same information, but both are provided so YOU can pick which is easlier for YOU to read, use, and understand.
external image UnitCircle.gifexternal image Unit_Circle_Angles.png
Key numbers on the unit circle:

30o π/6:
cos=√3/2
sin= 1/2
tan=√3/3
45o π/4:
cos=√2/2
sin=√2/2
tan= 1
60o π/3:
cos= 1/2
sin=√3/2
tan=√3

Still don't get it? Here are some videos to help ease your mind a little: