UNIT CIRCLE

Review:

• Unit Circle – a circle drawn around the origin, with radius 1

You can create right triangle using the unit circle, using the radius as the triangle hypotenuse

Remember..

Sinθ = = y

Cosθ = = x

Tanθ =

Examples:Use the unit circle to find:

1) Cos (180°)

2) Sin(-90°)

• Using 30-60-90 triangles, find the sine, cosine, and tangent of 30 °in RADICAL form assuming the angle is on the unit circle.. (no decimals)

• Using 45-45-90 triangles, find the sine, cosine, and tangent of 45 °in RADICAL form assuming the angle is on the unit circle.. (no decimals)

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Remember the signs of the quadrants

http://lelandmath.files.wordpress.com/2013/10/screen-shot-2013-10-14-at-7-19-46-pm.png

1) What is the sine of 135?

2) What is the cosine of 210?

3) What is the cosine of 30?

4) What is the sine of 390?

5) What is the cosine of -90?

6) What is the tangent of 45?

7) What is the cosine of π/3?