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Chain rule and cylindrical coordinates

  1. Jan 20, 2012 #1
    I'm trying to understand this one derivation but this one part keeps messing me up;

    theta = tan^-1 (y/x)
    r^2 = x^2 + y^2

    d theta/ d x = y/ (x^2 + y^2) how did they get this line?
     
  2. jcsd
  3. Jan 20, 2012 #2

    Char. Limit

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    Gold Member

    You just need to differentiate arctan(y/x) wrt x. Assume y is a constant for the purposes of this integration, of course.
     
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