Talk:Inflection point
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I have expanded this, and corrected a few errors including that the second derivative at a point of inflection can be non-zero. Also added the term 'saddle-point' for 'non-stationary point of inflection'. And made clear that in principle there is no limit to how high an order of derivative you might need to go to if you are using that method. 158-152-12-77 01:38, 24 August 2005 (BST)
[edit] Inconsistent definition of Saddle Point
The definition in this article differs substantially from the saddle point article. One or both need to be fixed to show the correct definition (or both definitions, if both are correct). I have never heard of the def in this article, but am familiar with the surface def in the separate saddle point article. However, that doesn't mean this def isn't also correct, as many terms have multiple meanings. StuRat 19:16, 24 August 2005 (UTC)
- Your graphs are excellent - they add a lot to the article. The definition of 'saddle point' in the saddle point article is incomplete, because it does not cover the case of a function of a single variable. This is covered properly in the Mathworld definition, namely "A point of a function or surface which is a stationary point but not a extremum" (i.e. not a local extremum).
- 158-152-12-77 21:41, 25 August 2005 (BST)
- I have amended saddle point article.
- 158-152-12-77 00:11, 26 August 2005 (BST)
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- Thanks. StuRat 23:18, 25 August 2005 (UTC)
[edit] Font problem
In four places towards then end of the article, when the first derivative is mentioned, it's impossible for me to see the apostrophe after the "f", so I thought the function itself was being referred to, and I got really confused. I really wish I could fix this myself, but I have no idea how.
- The only way I can see to make it more visible is to add spaces:
HOW IT NOW APPEARS: f'(x)
WITH SPACES ADDED : f ' (x)
- Should we do that ? StuRat 21:34, 2 December 2006 (UTC)
[edit] Definition vs. Property
From the definitions:
a point on a curve at which the tangent crosses the curve itself.
This is a property of inflection points, but in no way defines them: tangents can cross the curve in many points, most of which, in some cases, are not inflection points. See Tangent.
Diego.pereira 20:49, 10 March 2007 (UTC)
