SOLUTION: Simplify completely: √(1 + cos80°​)/2)

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Question 1030817: Simplify completely: √(1 + cos80°​)/2)
Answer by ikleyn(52852) About Me  (Show Source):
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Simplify completely: √(1 + cos80°​)/2)
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Use the formula for half-argument

sqrt%28%281%2Bcos%28alpha%29%29%2F2%29 = cos%28alpha%2F2%29

(see the lesson  Trigonometric functions of half argument  in this site).

You will get

sqrt%28%281%2Bcos%2880%5Eo%29%29%2F2%29 = cos%2840%5Eo%29