Michael J. answered • 11/28/16
Tutor
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Effective High School STEM Tutor & CUNY Math Peer Leader
Use the addition angle identity for cosine.
cos(30 + 45) =
cos(30)cos(45) - sin(30)sin(45) =
These trig terms are values on the unit circle that you should be able to easily identify. Find them and simplify the expression.
