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Easy integral

  1. Aug 10, 2010 #1
    This is not homework. I ran across this question in a book store a few minutes ago and cant seem to finish it...

    R= int(x,0,b
    S=int(cos(x),0,b
    for what value of b (a positive constant) does R=S?

    1/2x^2,0,b=1/2b^2
    sin(x),0,b=sin(b)

    1/2b^2=sin(b)

    Its been a while.. but I should be able to do this... thanks
     
  2. jcsd
  3. Aug 10, 2010 #2

    Mark44

    Staff: Mentor

    The integrals are easy enough, but I don't think the equation you ended with has an elementary solution. One approach would be to use numeric techniquest to get an approximate solution. Another approach might be the Lambert W function.
     
  4. Aug 12, 2010 #3
    Thank you! I assumed it had a smaller function because it was in a very low level book. I think it is mean to be entered into a calculator at the last point or be cycled through an approximation algorithm.
     
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