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

I am reading about differencial exact form, and i dont understand

  1. Oct 1, 2011 #1
    i am reading about differencial exact form, and i dont understand why

    [tex] d \theta [/tex] is not a exact...

    i think that is because [tex] d \theta [/tex] is not a total derivative of some function, since

    [tex] d \theta = \frac{1}{x^2+x^2} (-y dx+xdy)[/tex] is not definned globally in x,y = 0,0....

    ¿is correct?
     
  2. jcsd
  3. Oct 1, 2011 #2
    Re: question

    I think the region where it is not exact is R^2-{(0,0)},

    and one reason is that any candidate for a form θ with

    dθ= (xdy- ydx)/ (x2+y2) would agree

    with the arctan function, i.e., the angle function in polar coordinates

    ( set r2=x2+y2 , and work with polar coordinates)

    and there is no global angle function defined on R2-{0,0}
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook