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March 11th, 2011, 09:33 AM   #1
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Solve equation

All Ive got so far is
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March 11th, 2011, 10:25 AM   #2
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Re: Solve equation

So far, so good.
Now replace sin^2(x) with 1 - cos^2(x) in both places, and you should get a quadratic equation "in cos(x)".

ie, if you sub U = cos(x), you'll be able to rewrite as
aU^2 + bU + c = 0 and solve by usual methods.
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March 11th, 2011, 06:47 PM   #3
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Tank271, this should be very easy to solve if you know the trigonometric identities cos 2x = cos²x - sin²x and sin²x + cos²x = 1.
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