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Integral for a differential equation problem

  1. Apr 10, 2008 #1
    i'm stuck on this relatively simply integral for a differential equation problem ...

    | du / cos(pi/4 - u )
    where | denotes the integral sign

    some help ?
  2. jcsd
  3. Apr 10, 2008 #2


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    Hi sihag! :smile:

    Hint: substitute v = u - π/4. :smile:

    (and copy the symbols below for future use! :smile:)
  4. Apr 10, 2008 #3

    Gib Z

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    After letting [itex]\frac{\pi}{4} - u =x[/itex], all you need to know is [tex]\int \frac{1}{\cos x} dx = \log_e | \frac{1+\sin x}{\cos x} | + C[/tex].
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