Searching for formulas?

Question

Is there a site to search for formulas? I often come up with formulas that I would like to know the name, where they are used or what they are related to. One would type, for example, $\sin(a)\cos(b)+\sin(b)\cos(a)$ and it would intelligently associate it with the sum of sines formula. I know this would be no trivial service but I find it would be a great tool.

I think there was no need for me to check but anyway I just checked. Wolfram Alpha did it. — , Mar 15 '12 at 09:41
There are many lists of formulae on the internet, but if you want something which will parse what you write then you want a computer algebra system — Henry, Mar 15 '12 at 09:46

score 4 · Answer 1 · edited Mar 16 '12 at 17:33

4

What about this? http://www.wolframalpha.com/

edited Mar 16 '12 at 17:33

The Chaz 2.0

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answered Mar 15 '12 at 09:41

eccstartup

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or even this link (see "alternate form") – Henry Mar 15 '12 at 09:44
ac/(b^2-a^2) won't say it's to the closest point of a line in relation to origin - which is something I'd like to check ): – Dokkat Mar 15 '12 at 15:21
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Actually, the best would probably be "What about Wolfram Alpha?" with a link attached to the words Wolfram Alpha. – GeoffDS Mar 16 '12 at 17:40

score 4 · Answer 2 · edited Mar 16 '12 at 04:16

4

Unfortunately the existing search engines do not have that capability yet. You may check back in a year, there will be. (Trust me!)

In the meanwhile, maybe this one can be of some help

edited Mar 16 '12 at 04:16

Quixotic

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answered Mar 15 '12 at 12:12

Jeremy Carlos

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score 4 · Answer 3 · edited Mar 16 '12 at 17:35

4

I think more specifically Dokkat is looking for http://www.jackpo.org/files/formulas.pdf (something of this sort)

edited Mar 16 '12 at 17:35

The Chaz 2.0

10,464

answered Mar 15 '12 at 12:15

Kirthi Raman

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score 1 · Answer 4 · answered Mar 16 '12 at 04:24

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Wolfram|Alpha is the kind of thing you're looking for. For now, unfortunately, there aren't so many engines which allows you to search for knowledge rather than just results. For the sake of posting an answer though, I have heard about The Springer LaTeX search http://www.latexsearch.com/ but I'm not sure how useful could it be.

Morals of the story, you can always use a combination of Google, W|A, math.SE search bar, and question posting.

answered Mar 16 '12 at 04:24

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@KannappanSampath I'm glad you're back! – Mar 16 '12 at 16:27

score 0 · Answer 5 · answered Jun 14 '13 at 17:37

The search engine at formulasheet.com lets you search for formulas by typing in keywords (it also provides search suggestions). It searches Wikipedia's vast array of formulas as well as user-shared formulas and a small but growing formula database of their own. It does not however provide a means to search based on the source such as sin(a)cos(b)+sin(b)cos(a) as you requested, but it does do the reverse, for example http://formulasheet.com/#q|ev|Sine%20sum%20and%20difference%20identity.

Searching for formulas?

5 Answers5