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Homework Help: Find th length of th line x = int sqrt(sec(t)^4 - 1)) from 0 to y

  1. Feb 10, 2008 #1
    1. The problem statement, all variables and given/known data

    definate integral to find length of line

    x = int [sqrt( (sec t)^4 - 1)
    integrate from 0 to y with -pi/4 < y > pi/4
    it is actually y is equal or more/less than pi/4

    3. The attempt at a solution

    Ive worked out that the length of the line will be the same from -pi/4 to 0 as 0 to pi/4,
    giving me

    x = 2*int(sqrt( (sec t)^4 - 1)
    integrating from 0 to pi/4,
    im struggling with the integral, i know it must be substitution and i ve tried numerous trig identities just been coming up blank so far. a little push in the right direction would be great
  2. jcsd
  3. Feb 10, 2008 #2
    sorry that was meant to be y is equal or more than -pi/4 and y is equal or less that pi/4
  4. Feb 10, 2008 #3
    dont worry about it i figured it out
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