SOLUTION: Sin x = 4/5 where 0 <= d < pi/2 Find tan2x

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Question 1063467: Sin x = 4/5 where 0 <= d < pi/2
Find tan2x
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
Sin x = 4/5 where 0 <= d < pi/2
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I'll assume you mean 0 <= x < pi/2
Find tan2x
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sin^2 + cos^2 = 1 ------ the Pythagorean Identity. Remember it.
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cos(x) = sqrt(1 - sin^2(x)) = sqrt(1 - 16/25) = 3/5
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sin(2x) = 2sin(x)cos(x) = 24/25
cos(2x) = 7/25 -- Using the same method as above.
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tan(2x) = sin(2x)/cos(2x)
tan(2x) = 24/7