SOLUTION: show that cos(2arcsinx)=1-x^2

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Question 855298: show that cos(2arcsinx)=1-x^2
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
show that cos(2arcsinx)=1-x^2
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Let t be "the angle whose sin is "x"} = arcsin(x)
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cos(2t) = 1 - 2sin^2(t)
But sin(t) = x
So, cos(2(arcsin(x)) = 1-2x^2
Cheers,
Stan H.
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