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Trigonometry

Sum to Product Identities

QuestionAnswer
sinα+sinβ 2sin((α+β)/2)cos((α-β)/2)
sinα-sinβ 2sin((α-β)/2)cos((α+β)/2)
cosα+cosβ 2cos((α+β)/2)cos((α-β)/2)
cosα-cosβ -2sin((α+β)/2)sin((α-β)/2)
Created by: ed_delao
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