SOLUTION: Simplify the expression.
Cos(2arctan(x))
arctan is just the inverse of tan Example tan^-1
i keep getting (1-x^2)/(1+x) althoutgh it keeps saying that its wrong
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Trigonometry-basics
-> SOLUTION: Simplify the expression.
Cos(2arctan(x))
arctan is just the inverse of tan Example tan^-1
i keep getting (1-x^2)/(1+x) althoutgh it keeps saying that its wrong
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arctan is just the inverse of tan Example tan^-1
i keep getting (1-x^2)/(1+x) althoutgh it keeps saying that its wrong Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! Simplify the expression.
Cos(2arctan(x))
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Use the double-angle formula cos(2w) = 1-2sin^2(w)
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In your problem w = arctan(x)
If the tangent of w is x/1 then the sin(w) = x/sqrt(x^2+1)
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So cos(2arctan(x)) = 1 - 2[x/sqrt(x^2+1)]^2 = 1 - 2[x^2/(x^2+1)]
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Cheers,
Stan H.
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