Who Discovered the Trig Sum Formulas?

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Discussion Overview

The discussion centers around the historical origins of the trigonometric sum formulas, specifically who first derived them and the context of their derivation.

Discussion Character

  • Debate/contested
  • Meta-discussion

Main Points Raised

  • One participant presents the trigonometric sum formulas and asks who first derived them, along with inquiries about the timing and methodology of their derivation.
  • Another participant humorously claims that Julia Ward Howe derived the formulas in 1861, linking it to a Civil War song, which is met with confusion by others.
  • A later reply expresses confusion regarding the joke about Julia Ward Howe and requests more serious comments on the topic.
  • Participants engage in light-hearted banter about singing the song associated with the joke, indicating a shift away from the original inquiry.

Areas of Agreement / Disagreement

There is no consensus on the historical derivation of the trigonometric sum formulas, and the discussion includes both humorous and serious inquiries without resolution.

Contextual Notes

The discussion lacks specific historical references or citations regarding the derivation of the trigonometric formulas, and the humorous contributions may distract from the original question.

ImAnEngineer
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sin(a + b) = sin(a)cos(b) + cos(a)sin(b)
sin(a - b) = sin(a)cos(b) - cos(a)sin(b)

cos(a + b) = cos(a)cos(b) - sin(a)sin(b)
cos(a - b) = cos(a)cos(b) + sin(a)sin(b)

Who first derived them? When, and how?

Thanks
 
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ImAnEngineer said:
Who first derived them? When, and how?

Not how, but Howe … Julia Ward Howe, in 1861, derived them, and they became a Civil War marching song, to the tune now known as the Battle Hymn of the Republic. :wink:
 
tiny-tim said:
Not how, but Howe … Julia Ward Howe, in 1861, derived them, and they became a Civil War marching song, to the tune now known as the Battle Hymn of the Republic. :wink:
If it's a joke... sorry but I don't get it.
 
ImAnEngineer said:
If it's a joke... sorry but I don't get it.

:rolleyes:

try singing it! :smile:
 
tiny-tim said:
:rolleyes:

try singing it! :smile:

Struggling to get a nice melody... :P

Any serious comments?
 

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