Unit Circle Double Angle Derivations

  • Context: Undergrad 
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Discussion Overview

The discussion revolves around the derivation of double angle formulas using the unit circle, with participants reflecting on their experiences and mistakes in geometric reasoning. The conversation touches on the reliability of diagrams and the importance of verification in mathematical and physical contexts.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant reflects on a mistake made by assuming an equilateral triangle, leading to confusion in deriving double angle formulas.
  • Another participant warns against trusting diagrams, suggesting they can be misleading or incorrect.
  • A different viewpoint emphasizes the importance of verification and skepticism in both mathematics and physics, citing examples from software engineering and common misconceptions.
  • There is a mention of the challenges in visualizing certain geometric concepts, particularly in relation to the term "isosceles" after a correction from a neighbor.

Areas of Agreement / Disagreement

Participants express differing views on the reliability of diagrams and the necessity of verification in problem-solving. There is no consensus on the best approach to take when dealing with geometric derivations or the interpretation of visual aids.

Contextual Notes

Some participants express uncertainty about their previous assumptions and the implications of their reasoning, indicating a need for clarity in definitions and geometric properties.

Who May Find This Useful

This discussion may be of interest to those studying geometry, trigonometry, or anyone involved in mathematical problem-solving, particularly in contexts where visual representations are used.

aronclark1017
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Here I made a terrible mistake of assuming this to be an equilateral triangle and set 2sinx=1 => x=pi/6. Although this did derive the double angle formulas it also led into a terrible mess trying to find all the combinations of sides. I must have been tired and just assumed 6x=180 and 2sinx=1. By that time, I was so mindset that I nearly scolded a person for even saying 90-x. I wonder if this is a case of biased observation that seeks to dis credit me like Jesus of Nazareth since in reality it is a miracle I was even able to solve this one that way. Don't be a dummy else could possibly spin off into infinity before simply making the simple decision to use 90-x.
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Never trust a diagram sometimes they are close but often it could be a trick.

Like making an equilateral triangle with angles of 70 degrees each or worse 90 degrees.

I recall one poster here showing a diagram of a figure but upon solving you found out it was a segmented straight line. Apparently, it was for a job interview.
 
Heh dry idea..I think is to never trust one person by self when it come to mechanics no debugger else is dry idea even with PhD.
 
Another way to say it is:

Trust but verify. While we can’t test everything, we should test those things that we are skeptical of and always remember to keep an open mind as all things are suspect.

As a software engineer, we write code, add bugs and then have to find them. But every once in awhile, the bug is in some third party code, invisible to the developer and it takes a lot of time to ferret out whats going on.

Another aphorism is: Extraordinary ideas require extraordinary proof that they are true.

This comes up a lot in physics where people think Einstein CAN’T be right because it goes against their daily experience or Quantum Mechanics because its too spooky.

Or the Flat Earthers who believe the world can’t be a pear-shaped oblate spheroid because their daily experience is that Earth is mostly flat as far as the eye can see.

All these group have yet to provide extraordinary evidence to prove their case.
 
Although it's hard to imagine this contraption in motion at first glance. I think that's why they say "isosoles". after being corrected on my equilateral derivation by a neighbor 😡😡
 
Thread is closed for Moderation.
 
aronclark1017 said:
Heh dry idea..I think is to never trust one person by self when it come to mechanics no debugger else is dry idea even with PhD.
aronclark1017 said:
Although it's hard to imagine this contraption in motion at first glance. I think that's why they say "isosoles". after being corrected on my equilateral derivation by a neighbor 😡😡
Thread is reopened provisionally.

@aronclark1017 -- can you please clarify what you are trying to say in your last couple of posts? Thanks.
 

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