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Homework Help: Trigonometric antiderivatives

  1. Feb 8, 2012 #1
    1. The problem statement, all variables and given/known data


    I don't see how they're going from

    sec x cot x to csc x


    csc x tan x to sec x

    The derivative of sec x is sec x tan x not csc x tan x
    and the derivative of csc x is -csc x cot x

    and if it's an identity then they didn't care to inform me of that at this website

  2. jcsd
  3. Feb 8, 2012 #2


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    Homework Helper

    Express sec x, csc x, cot x and tan x in terms of sin x and cos x first.

    Sure, but what's the relevance of this? They weren't integrating at that stage, merely simplifying using trig identities.
  4. Feb 8, 2012 #3


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    You should not only recognize the trig identities, but different variations of them. For instance,
    [itex]\tan \theta = \frac{\sin \theta}{\cos \theta}[/itex].
    But it is also true that
    [itex]\tan \theta = \sin \theta \sec \theta[/itex].
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