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EricLengyel

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How many people were taught that the formulas for the dot product (x₁x₂ + y₁y₂ + z₁z₂) and cross product (y₁z₂ − y₂z₁, z₁x₂ − z₂x₁, x₁y₂ − x₂y₁) are simply definitions and cannot be derived?

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@EricLengyel Derived in high school (higher level maths only).

@EricLengyel Derived in high school (higher level maths only).

Properties5
typearchive
sourcetwitter
date2020-02-17
tagsarchive, twitter, ericlengyel
description@EricLengyel Derived in high school (higher level maths only).

Feb 17, 20201 min read

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  • URL: https://x.com/Peter_Blackburn/status/1229240719241445376
  • Author: Peter Blackburn (@Peter_Blackburn)
  • Posted: 2020-02-17 03:06:40

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1/ @Peter_Blackburn

@EricLengyel

Derived in high school (higher level maths only). Ignored in university, only calculus covered:(

2/ @EricLengyel

@Peter_Blackburn

What was the gist of the derivation you saw in high school?

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  • How many people were taught that the formulas for the dot product (x₁x₂ + y₁y₂ + z₁z₂) and cross product (y₁z₂ − y₂z₁, z₁x₂ − z₂x₁, x₁y₂ − x₂y₁) are simply definitions and cannot be derived?

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