SOLUTION: Use an appropriate half-angle formula to find the exact value of the expression.
cos(-112.5)
I did the problem and got sqrt(2-sqrt(2))/(2) and its wrong. Help me solve this and
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-> SOLUTION: Use an appropriate half-angle formula to find the exact value of the expression.
cos(-112.5)
I did the problem and got sqrt(2-sqrt(2))/(2) and its wrong. Help me solve this and
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Question 425048: Use an appropriate half-angle formula to find the exact value of the expression.
cos(-112.5)
I did the problem and got sqrt(2-sqrt(2))/(2) and its wrong. Help me solve this and find my mistake. Please and thank you! Answer by Alan3354(69443) (Show Source):
You can put this solution on YOUR website! cos(a/2) = ± sqrt( (1+cos(a))/2)
cos(-225) = -sqrt(2)/2
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cos(-112.5) = sqrt(0.5 - sqrt(2))/4)
= sqrt(0.5 - sqrt(2))/2
=~ -0.38268
