Question 640253
Prove the identity:

      2 tan x 
______________ = sin 2x

  1 + tan^2 x
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Prove the identity:

      2 tan x 
______________ = sin 2x

  sec^2 x
-----------------
2tan(x) = sin(2x)*cos^2(x)
2tan(x) = 2sin(x)cos^3(x)
Not an identity.