Geometrical representation of the nth derivative

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Discussion Overview

The discussion revolves around the geometrical representation and physical interpretation of higher-order derivatives of functions. Participants explore the meanings of the first, second, third, and higher derivatives, focusing on their implications for the shape and behavior of curves.

Discussion Character

  • Exploratory, Technical explanation, Conceptual clarification, Debate/contested

Main Points Raised

  • One participant notes that the first derivative indicates the slope of a tangent at a point, while the second derivative relates to the concavity of the function's curve.
  • Another participant suggests that the third derivative reflects the rate of change of the slope, which they describe as the "acceleration of the slope," but expresses uncertainty about its geometric implications.
  • A different participant mentions that knowing a finite number of derivatives provides local properties of a curve, while knowledge of all derivatives can yield global properties through Taylor's theorem, indicating a limitation in using operators involving all orders for local theories.
  • One participant expresses surprise at the existence of the third derivative, highlighting the learning aspect of the discussion.
  • Another participant points out that the second derivative may not always indicate concavity, using the functions f(x) = x^4 and g(x) = -x^4 as examples where the second derivatives are the same at a point, but higher derivatives reveal different orientations. They also introduce the term "jerk" for the third derivative in the context of physical applications and mention the existence of limits on higher derivatives for practical uses.

Areas of Agreement / Disagreement

Participants express varying levels of understanding and interpretation of higher-order derivatives, with no consensus on their geometric representations or physical meanings beyond the second derivative. The discussion remains unresolved regarding the implications of higher derivatives.

Contextual Notes

Some participants acknowledge limitations in their understanding of higher derivatives and the conditions under which certain derivatives provide meaningful information about curves.

AlbertEinstein
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The first derivative represents the slope of a tangent at a point on the function's curve.
The second derivative represents the concavity of the function's curve.
However I am unable to figure out what the other derivatives of a function represent either physically or geometrically.
Pleae help.
 
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Well if the 2nd derivative measures the speed at which the slope is changing , the 3rd derivative measures the speed of the speed at which the slope is changing, i.e. the acceleration of the slope.

That's as deep as I can get. I don't know what that says about the geometry of the curve.
 
One thing I can tell you is that while knowing a finite number of derivatives of a curve at a point gives you local properties of the curve, knowing the derivatives of all orders tells you global properties via Taylor's theorem. For example, when physicists want a local theory, they cannot use operators that involve derivatives of all orders.
 
Hmm... did not know that there was a 3rd dirivative. Guess your learn something new every day!
 
Sometimes the second derivative yields no information about concavity. Consider the two different functions f(x) = x^4 and g(x) = -x^4. These two functions have different concavities, but if evaluated at (0, 0), their second derivative is the same. A higher derivative will reveal their different orientations at (0, 0).
Physically, the name "jerk" is given to the third derivative of a position function with respect to time. There are standardized limits placed on jerk for things as simple as starting and stopping trains. Limits are placed on much higher derivatives for sensitive instruments like the Hubble telescope. Very few people have deemed it necessary to give names to these quantities beyond fourth derivative, fifth derivative and so on.
 
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