Talk:Trigonometric functions

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Trigonometric functions is a former featured article. Please see the links under Article milestones below for its original nomination page (for older articles, check the nomination archive) and why it was removed.
This article appeared on Wikipedia's Main Page as Today's featured article on March 6, 2004.
Article milestones
DateProcessResult
December 12, 2003Featured article candidatePromoted
September 20, 2004Featured article reviewKept
July 19, 2008Featured article reviewDemoted
Current status: Former featured article

Article

i wanted to learn something - completely impossible from this article, this is just a reference for those who know all of this material already. — Preceding unsigned comment added by 108.84.184.142 (talk) 21:44, 10 March 2013 (UTC)

• i agree, the definition is supposed to be comprehensible without too much reference or dependence on other "terms". it was obviously written by those who already understand the subject and can't intuit how to explain it for those who don't. 197.134.147.164 (talk) 11:03, 15 May 2013 (UTC)
• I also agree. It is so disappointing that there are no surface plots of the absolute value for the complex trig functions. This "Domain coloring" is lame and impossible to decipher (it is completely ridiculous that I have to ask maple or mathematica to gain a reasonable quantitative understanding) 69.131.208.241 (talk) 21:49, 24 November 2021 (UTC).
The domain coloring method is "lame"? Please explain. It is true, though, that the type of the coloring used in the article (introduced by the user Nschloe) is very non-standard. A1E6 (talk) 16:43, 25 November 2021 (UTC)

I would like to point out that an encyclopedia article is not supposed to be the first place to learn about something. First consult a textbook, then for things that a textbook might leave out, or might get wrong, or might be slanted about, then go consult the encyclopedia. Or, first consult the encyclopedia in order to get a very vague and general idea of what is involved in the topic, what it is about, and a list of textbooks or sources in its bibliography. So these comments are invalid. 98.109.232.157 (talk) 05:06, 1 September 2014 (UTC)

OK, almost eight years old, but this statement is too outrageously ridiculous to leave alone. OF COURSE, an encyclopedia is supposed to be the first place to learn about something. That's exactly why people used to buy Encyclopedia Britannica, Encyclopedia Americana, Colliers, Funk & Wagnalls ... A question would come up in the family--that's where they'd go to look; Mom and Dad would encourage the kids to look things up. And yes, I think that if an encyclopedia is supposed to be general interest (which I think Wikipedia is) and not a specialist reference for specialists, it should make an effort to say what a thing is about in some way--at least as much as the topic will allow--that anybody can understand it. On tech and math subjects, Wikipedia falls woefully short in that regard. Uporządnicki (talk) 14:42, 30 April 2021 (UTC)
Wikipedia is a "reference" (can a math reference even be labeled as "non-specialist"?), not a textbook (WP:NOTTEXTBOOK). Sometimes, the articles are too technical and are marked as such, but that rarely happens. This article is not one of them and the editors are doing their best to make the article understandable. But I don't think it's possible to write a math reference so that anybody can understand it. A1E6 (talk) 16:38, 25 November 2021 (UTC)

Boy I hope that is not the purpose of Wikipedia. That would make it pretty useless. 4 July 2017 (JCBoone) — Preceding unsigned comment added by Joseph C Boone (talkcontribs) 21:50, 4 July 2017 (UTC)

Algebraic value of sin 45°

@DVdm: reverted my change from

${\displaystyle \sin {\frac {\pi }{4}}=\sin 45^{\circ }={\frac {\sqrt {2}}{2}}={\frac {\sqrt {2}}{2}}}$

to

${\displaystyle \sin {\frac {\pi }{4}}=\sin 45^{\circ }={\frac {\sqrt {2}}{2}}={\frac {1}{\sqrt {2}}}}$

with the comment "Sqrt(2)/2 is much more common than 1/sqrt(2) in the literature". Though I understand that √2/2 is more common, the line gives it twice. I wonder if it may help learners to know that both expressions are valid, should they come across the rarer form. Does anyone have any thoughts on this?

Cheers,
cmɢʟeeτaʟκ 22:55, 5 July 2020 (UTC)

Crissov added the accidentally duplicate values on 23 January 2020. Previously, the values looked like this and the duplication probably came from the "easy way to remember" values. Probably best to omit. Johnuniq (talk) 23:57, 5 July 2020 (UTC)
Yes, I already removed the duplicate values: [1]. - DVdm (talk) 06:33, 6 July 2020 (UTC)

Asymptote oversight?

I'm surprised that there's no mention at all of how the tangent function has a vertical asymptote at θ = (k + 1/2)π, as it's what clearly delineates tan from sin and cos. Tangent (function) redirects here so I think it deserves mentioning, but I'm not sure on the best place for it as this article is quite dense already. Snizzbut (talk) 16:16, 28 February 2021 (UTC)

Good point. Also, the basic properties as functions of trigonometric functions were also lacking. I have added them, with a figure, at the beginning of section "In calculus". D.Lazard (talk) 17:24, 28 February 2021 (UTC)

Values of zero in table?

In the "Simple algebraic values," is there some reason not to show zeroes for the sine and tangent of 0°, and for the cosine and cotangent of 90°? Right now, those spaces are blank. That seems odd, considering that other spaces on the table show infinity; that's an arguable point--the zeroes are not. Uporządnicki (talk) 13:52, 19 August 2021 (UTC)

Done. I replaced the tagged zeros with templates as in the first column. See [2]. - DVdm (talk) 14:05, 19 August 2021 (UTC)
Test:
"<math>0</math>" produces "${\displaystyle 0}$" (nothing), where "{{math|0}}" produces "0".
"<math>1</math>" produces "${\displaystyle 1}$".
"<math>00</math>" produces "${\displaystyle 00}$".
"<math>01</math>" produces "${\displaystyle 01}$".
"<math>0=0</math>" produces "${\displaystyle 0=0}$".
"<math> 0</math>" produces "${\displaystyle 0}$". HA, we need a space!
Strange - DVdm (talk) 14:10, 19 August 2021 (UTC)
For consistency, I went back to "<math> 0</math>" with the spaces: [3]. - DVdm (talk) 14:33, 19 August 2021 (UTC)
Silly me! I was just going to go in and type "0"! Uporządnicki (talk) 16:37, 19 August 2021 (UTC)
Not silly, as it seems to produce the same as "{{math|0}}". I tried that but that would give inconsistent results when rendering math as PNG. I've asked at Wikipedia:Village pump (technical)#Math 0. Let's see what they say... - DVdm (talk) 17:07, 19 August 2021 (UTC)

Update. Known bug, introduced today: Phab:T288846#7294135, [4] - DVdm (talk) 21:28, 19 August 2021 (UTC)

Well, I meant "silly me" ironically--tongue-in-cheek suggesting that it was silly to think of trying the obvious: I want to show 0, type 0. I'll have to take your word for it that it will raise some sort of problem in Papua-New Guinea. Uporządnicki (talk) 11:54, 20 August 2021 (UTC)