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Homework Help: Integral of cotx squared

  1. Sep 30, 2009 #1
    1. The problem statement, all variables and given/known data
    find the integral of (cscx)2 between pie/6 to pie/2

    3. The attempt at a solution

    cot2x = 1 / sin2x * cos2x / cos2x
    which becomes..
    tan2x * sec2x
    then i substituted u for tan x, and turned the integral into..
    u2du = u3 / 3
    which is..
    tan3x / 3 between pie/6 and pie/2.

    However, tan is undefined at pie/6!! what do i do?
  2. jcsd
  3. Sep 30, 2009 #2
    No, that last line should be cot2x * sec2x, and the cot in the first line should be csc.

    That's not true; it is defined at [itex]\pi[/itex]/6. What is sin[itex]\pi[/itex]/6 and cos[itex]\pi[/itex]/6? Put sine over cosine.
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