Posted by **kim** on Saturday, May 24, 2008 at 2:43am.

using the unit circle evaluate cos and sin for 30

- trig -
**Reiny**, Saturday, May 24, 2008 at 8:04am
You should be familiar with the ratio of sides of a 30,60,90º triangle.

use them to fill in the coordinates of all your critical values of P(cosα,sinα) on the unit circle

here sin30º = 1/2

cos30º = √3/2

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