Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Boundaries Change With U-Sub? Huh?

  1. Nov 29, 2011 #1
    So, I've been trying to figure out why the boundaries change in the example below. It seems like the boundaries change from [0,2] to [1,17] and I can't discover why this is. Ideas?

    http://img841.imageshack.us/img841/3808/skjermbilde20111129kl52.png [Broken]
    Last edited by a moderator: May 5, 2017
  2. jcsd
  3. Nov 29, 2011 #2
    You're just making a substitution. What is the theorem that says that you can calculate integrals by substitution?? What does it say about the bounds?
  4. Nov 29, 2011 #3
    I don't know what theorem this is. What theorem is it?
  5. Nov 29, 2011 #4


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    If u = 1+4t2, what u values correspond to your t value limits?
  6. Nov 29, 2011 #5
    Oh! I understand this now: 4t2 + 1, where t=2,0 gives 17 and 1, respectively.

    Okay. But, just out of curiosity, what theorem is this? I still don't know.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook