SOLUTION: How do I find the exact value of 1-cos squared10 degrees - Cos squared80 degrees? Can you please go step by step so I can learn how to do it properly? Thank you Note: There is

Algebra ->  Trigonometry-basics -> SOLUTION: How do I find the exact value of 1-cos squared10 degrees - Cos squared80 degrees? Can you please go step by step so I can learn how to do it properly? Thank you Note: There is       Log On


   



Question 728484: How do I find the exact value of 1-cos squared10 degrees - Cos squared80 degrees? Can you please go step by step so I can learn how to do it properly? Thank you
Note: There is nothing between the cos squared and the degrees on either side

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
How do I find the exact value of 1-cos squared10 degrees - Cos squared80 degrees?
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cos(80) = sin(90-80) = sin(10)
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1 - cos^2(10) - cos^2(80)
= 1 - cos^2(10) - sin^2(10)
1 - cos^2 = sin^2
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= sin^2(10) - sin^2(10)
= 0