SOLUTION: cos(120) +cos(30) Using the product to sum formula

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Question 945993: cos(120) +cos(30)
Using the product to sum formula

Answer by MathLover1(20850)   (Show Source): You can put this solution on YOUR website!


you are supposed to express as and change it to single angles with the standard formula


= ........since , , we have
=

=

=

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