1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Unsure where to start

  1. Jul 27, 2011 #1
    1. The problem statement, all variables and given/known data
    Howdy fellas, long time lurker, first time poster. If someone could get me started on the right track for this problem, it would be appreciated.

    Also, I'm not sure how to write equations yet, but I'll do my best to explain the problem clearly

    2. Relevant equations

    Int[1 to 2] Int[0 to x] of 1/(sqrt((x^2)+(y^2)))dydx

    3. The attempt at a solution

    As I said, not sure how to get started. My gut was telling me to raise the denominator to the -1/2 power and use the substitution rule? But I'm not sure.

  2. jcsd
  3. Jul 27, 2011 #2
    Hi FecalFrown! :smile:

    Let's start with the inner integral, this is


    where x is simply a constant. The trick is to factor x out of the square root, and then to do a trigonometric substitution [itex]\frac{y}{x}=\tan(\theta)[/itex]
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook