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Homework Help: Why does sin(t)cos(t) = x(1-x)^{1/2}

  1. Aug 17, 2008 #1
    I'm working on a differential equation, and my answer is

    sin(t)cos(t) which in the text, they jump from that straight to
    [tex] x(1-x^2)^{\frac{1}{2}} [/tex]

    I've forgotten a lot of what I learnt in my first few years of Uni and I just can't remember why they equal, I thouht it might be an identity, but I have looked on the net and can't find one... can someone please shed some light? Thanks
  2. jcsd
  3. Aug 17, 2008 #2
    Dont worry I worked it out
  4. Aug 17, 2008 #3

    George Jones

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    What is [itex]x[/itex]?
  5. Aug 17, 2008 #4
    was there a u-substitution or something earlier on? cause taking either sin(t) as x, or cos(t) as x, would give the second equation when rewritten in terms of x.
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