Post on 14-Jan-2016
The Unit CircleDr. Shildneck
Fall, 2014
The Unit Circle
• The Unit Circle is a circle of radius 1-unit.
• Since angles have the same measure regardless of the size of their terminal side, we generally speak about their trigonometric ratios by using angles as they rotate around a unit circle.
Special Angles
0o
90o
180o
270o
360o
30o
45o
150o
135o
225o 240o
330o
315o
60o 120o
210o
300o
Special Right Triangles
30 – 60 – 90
45 – 45 – 90
1
2
3
1
1
2
x 2
x 3
x 2
=
Trig Values on the Unit Circle
11
1 1
Trig Values on the Unit Circle
1
Trig Values on the Unit Circle
11
1 1
Trig Values on the Unit Circle
1
Trig Values on the Unit Circle
11
1 1
Completing the Unit Circle
• Know the patterns for 45’s
• Know the patterns for 60’s
• Know the SIGNS (cosine – x, sine – y)
Completing the Table
• Know the Unit Circle (sines and cosines)
• Find Tangent (y/x = sine/cosine)
• Know Reciprocals
Assignment
1) Complete Unit Circle2) Complete Table
Practice more than onceDownloadable on Blog