Talk:Trigonometry

Template:WP1.0

Etymology

Could we add a section on the etymology of the word "trigonometry" here? —Preceding unsigned comment added by 121.247.74.93 (talk) 13:31, 21 December 2010 (UTC)

I don't see how that's necessary

Tri-: three -gon-: angles -ometry: measuring Trigonometry: the measuring of triangles. 75.118.170.35 (talk)

Stop It

This page was really useful two days ago until someone dissected it. Stop breaking it up. 7/21/1p —Preceding unsigned comment added by 174.199.140.153 (talk) 16:06, 21 July 2010 (UTC)

Merge proposal

Suggest that this article is merged with "trigonometric functions" Ehrenkater (talk) 15:15, 25 December 2008 (UTC)

Graph

Does anyone have a new version of the sine/cosine (in radians) graph on this page? The two labels overlap. I don't know how to fix this. Quark1005 (talk) 04:59, 12 January 2009 (UTC)

GA Review

This review is transcluded from Talk:Trigonometry/GA1. The edit link for this section can be used to add comments to the review.

Result: Quick-fail

This article is not ready for GAN at this time due to non-compliance with quick-fail criterion #1: The article completely lacks reliable sources – see Wikipedia:Verifiability. I notice there are some books referenced in the References section, but they are not incorporated into the body of the article with inline citations. The three sources that are incorporated inline only support minor facts, and one is probably not reliable.

Before this article's next GAN run, here are a few additional issues to consider:

• The History section is anemic despite having its own article. It's okay to outsource details, but this section does not address the main issues of the topic (GA criterion #3).
• Per WP:CAP, image captions only end with a period if a complete sentence.
• MOS:IMAGE should be consulted to ensure that images are placed next to pertinent sections and that no new info is presented in the caption.

Best regards —Eustress ^talk 14:34, 23 February 2009 (UTC)

It has to do with two thing. —Preceding unsigned comment added by 71.207.86.13 (talk) 22:13, 21 August 2009 (UTC)

Illustration with law of sines and cosines

Laws of sines and cosines${\begin{aligned}{\frac {a}{\sin A}}&={\frac {b}{\sin B}}={\frac {c}{\sin C}}\\[5pt]\cos C&={\frac {a^{2}+b^{2}-c^{2}}{2ab}}\end{aligned}}$

I seem to be in a disagreement with User:Anonymous Dissident who objects to the formulas in the illustration to the right, saying "It seems redundant to repeat the formulae here, and the omission of the tangent law is a noticeable inconsistency. PNGs in captions can also be unfriendly." I find having the formulas in the caption quite helpful and see no problem with captions repeating information in the text. Rather than get into an edit war, I'd like other opinions.

I also don't understand the reasons for Anonymous Dissident's edits to the intro. Why is the fact that Trigonometry is taught in secondary schools to be mentioned before the fact that it has important applications? And why the objection to the mention that trig is an informal name?--agr (talk) 14:59, 28 October 2009 (UTC)

Redundancy is a bad thing. We are an encyclopedia, and the idea is to be robust. The simplicity of the diagram in question makes it best useful as a simple representation of the configuration discussed in the prose. Readers should be directed to read the text, and images should function as illustrations. The edits to the intro were made only because it disrupted the flow to have a one-sentence third paragraph only on spherical trigonometry. Originally, the bit about school courses was last, but – as you rightly noted – it seemed to indicate that spherical trigonometry is taught in high school. So I changed the order. I removed the mention of "trig" because it's implied by the hatnote, and out of place anyway. —Anonymous Dissident^Talk 05:23, 29 October 2009 (UTC)

Print encyclopedias have illustrations and I would expect one very similar to the one on the right to appear in more than one. The version you created, however, is indeed redundant, a very similar diagram appears earlier in the article. We are writing for a general audience, not specialists. Math is hard enough. Diagrams that help our readers should not be deleted out of some sense of purity. And as for "trig," no print encyclopedia would use header information in place of article content. I do like what you did with the animations tho.--agr (talk) 22:22, 29 October 2009 (UTC)

I can't do anything but re-iterate my points above. I suggest both our views are legitimate, and that we should wait for a third opinion. —Anonymous Dissident^Talk 06:15, 30 October 2009 (UTC)

Here is my humble opinion. One should avoid repeating information where possible. Since the formulas are located next to the figure, my preference would be to not duplicate the information. Regarding order of information, I would go with chronological order. One learns trig in school, then one uses it in the scientific or business world. So my preference would be to leave the order as is. Regarding the inclusion of the term "trig", that seems reasonable since it is probably used more than the full term itself. I would have no objection including a phase such as "commonly referred to as 'trig' " or some other such phrasing. Just my humble opinion. JackOL31 (talk) 01:58, 19 November 2009 (UTC)

graph mnemonics

Half the mnemonics in the graph with noted ratios are not explained. Maybe it needs a key? —Preceding unsigned comment added by 203.214.158.105 (talk) 06:23, 11 April 2010 (UTC)

Article lacks useful content

This article has very little content that would be useful to a reader not familiar with the subject. In particular, discussing the laws of sines and cosines without defining what those functions are seem pointless. There were at least some explanations in earlier versions of this article. Why were they cut? Articles are supposed to stand on their own. I'm inclined to restore some of this material.--agr (talk) 01:50, 30 May 2010 (UTC)

You may have seen the article in a vandalized state, someone deleted about half the material and it wasn't restored for 8 hours.--RDBury (talk) 12:51, 30 May 2010 (UTC)

Yup. Shudda looked at the history more carefully.--agr (talk) 16:30, 30 May 2010 (UTC)

SOHCAHTOA

I did a Google books search for references on the SOHCAHTOA mnemonic. The word "SOHCAHTOA" turned up hundred of hits, some even in fiction. On the other hand, phrase type mnemonics only came up a few times. This would seem to indicate that the word is much more successful as a mnemonic than any of the phrases and has entered the general culture. The phrases may be clever and amusing but it seems that few are really memorable, a requirement for a mnemonic, and fewer still are encyclopedic. Given this, I'm wondering if the Mnemonics section should be retooled to focus exclusively on the word.--RDBury (talk) 12:46, 30 May 2010 (UTC)

Misuse of sources

Jagged 85 (talk · contribs) is one of the main contributors to Wikipedia (over 67,000 edits; he's ranked 198 in the number of edits), and practically all of his edits have to do with Islamic science, technology and philosophy. This editor has persistently misused sources here over several years. This editor's contributions are always well provided with citations, but examination of these sources often reveals either a blatant misrepresentation of those sources or a selective interpretation, going beyond any reasonable interpretation of the authors' intent. Please see: Wikipedia:Requests for comment/Jagged 85. That's an old and archived RfC. The point is still valid though, and his contribs need to be doublechecked. I searched the page history, and found 18 edits by Jagged 85 (for example, see this edits). Tobby72 (talk) 20:00, 15 June 2010 (UTC)

Sinθ≠θπ÷180

I'm trying to figure out how to find the trigonometric functions of angles of non-quadrantal or non-special triangle angles. I came here to see if there was some formula to calculate those. The closest thing I've came up with is Sinθ≠θπ÷180. But the problem with that formula is the Sin1 doesn't 100% true unless you use 3 or 4 significant digits. I know why this is but I can't illustrate that on here. But this is true Sinθ<θπ÷180. π÷180 is 1/360 of a circle and not an straight line up from the y axis thus Sinθ<θπ÷180. If I could illustrate this, it would make a lot more sense. —Preceding unsigned comment added by 166.214.45.164 (talk) 00:07, 24 September 2010 (UTC)

A definate plus

Adding the polar graph with the trigonometric functions would be a good add. —Preceding unsigned comment added by 166.214.170.106 (talk) 01:32, 10 December 2010 (UTC)

*

"A common use of mnemonics is to remember facts and relationships in trigonometry. For example, the sine, cosine, and tangent ratios in a right triangle can be remembered by representing them as strings of letters, as in *SOH-CAH-TOA:"

Why the asterisk? 75.118.170.35 (talk) 16:18, 21 January 2011 (UTC)