SOLUTION: How can I express sin195 in terms of a reference angle?

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Question 880749: How can I express sin195 in terms of a reference angle?
Answer by josgarithmetic(39625) About Me  (Show Source):
You can put this solution on YOUR website!
Work to relate 195 degrees to differences from 90, or 180, or 270 or 360 degrees.

195 is a little more than 180 degrees.
195-180=15 degree difference, and this is in quadrant 3. Using how the Unit Circle is symmetric, the sine of 195 is the opposite of the sine of 15 degrees.

Very likely, you want to relate this to a more familiar reference angle.
15 degree is HALF the measure of 30 degree.

Directly using such a formula,
-sin%2815%29=-sqrt%28%281-cos%2830%29%29%2F2%29