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What does " to first order" mean ?

  1. Aug 26, 2015 #1


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    Hi. When using approximations such as g = n + h where h is much less than n ; what does " valid to first order in h" mean ? Does it mean include terms linear in h or does it mean drop those terms ?
  2. jcsd
  3. Aug 26, 2015 #2


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    It's the former. It's based on the idea of the amount - g in this case - being expressed as a Taylor series in h. To first order means including the constant term and the term that has ##h^1## but excluding all other terms that have ##h^k## for ##k>1##.
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