Visualizing the Dot Product Inequality of a, b & c in R^d

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Discussion Overview

The discussion revolves around the geometric visualization of the dot product inequality involving three vectors a, b, and c in R^d, specifically the condition a.b < c.b. Participants explore various interpretations and representations of this relationship in a geometric context.

Discussion Character

  • Exploratory
  • Conceptual clarification
  • Mathematical reasoning

Main Points Raised

  • One participant suggests that the inequality a.b < c.b can be interpreted geometrically as vector a having a lesser component in the direction of vector b compared to vector c, or that a has a more negative component than c.
  • Another participant proposes that the dot product can be visualized as a rectangle, where the area represents the product of the magnitudes of vectors a and b multiplied by the cosine of the angle between them.

Areas of Agreement / Disagreement

Participants express varying interpretations of the geometric implications of the dot product inequality, indicating that multiple perspectives exist without a clear consensus on a single visualization approach.

Contextual Notes

The discussion does not resolve the specifics of the geometric representations or the implications of the inequality, leaving open questions about the assumptions and definitions involved in the interpretations.

shybishie
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Suppose I have three vectors a,b and c in [tex]R^d[/tex], And, I have that a.b < c.b(assume Euclidean inner product). What are the ways to visualize relation between a,b and c geometrically? I realize this is slightly open-ended, but am looking for insight here. Thanks in advance.

PS: I have a thought or two, but I'd like to hear feedback before I give my view of the situation.
 
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[tex]\vec{a} \cdot \vec{b} < \vec{c} \cdot \vec{b}[/tex] can be interpreted geometrically as [tex]\vec{a}[/tex] having less of a component in the direction of [tex]\vec{b}[/tex] than does [tex]\vec{c}[/tex]. Or [tex]\vec{a}[/tex] has a more negative component than [tex]\vec{c}[/tex].
 
Thank you, markly. In retrospect, I should have framed this question to be less trivial sounding than it came out.
 
The dot product [tex]\vec{a} \cdot \vec{b}[/tex] can be visualized as a rectangle (see orange rectangle http://www.ies.co.jp/math/java/vector/naiseki_e/naiseki_e.html" ) having sides of length [tex]|\vec{a}|[/tex] and [tex]|\vec{b}| \mathrm{cos(\alpha)}[/tex].

This is because [tex]\vec{a} \cdot \vec{b} = |\vec{a}| \cdot |\vec{b}| \mathrm{cos(\alpha)}[/tex]
 
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