Question 728484
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