What is called?
By Alex Holyoake on Friday, October 11, 2002 - 11:19 am:

What is the symbol called that is used for partial differentiation? It's bugging me!!

I am calling it bob at the moment, but I don't think that would impress the Trinity admissions tutor!

By Geoff Milward on Friday, October 11, 2002 - 12:12 pm:

I always call it partial d, but perhaps there is a proper name; I'd be interested too

Geoff M

By Julian Pulman on Friday, October 11, 2002 - 01:00 pm:

"curly d"

By Arun Iyer on Friday, October 11, 2002 - 02:29 pm:

In the texts that i have read .. it is given as "dabba"..

(personally,i prefer to call it "del")

love arun

By Yatir Halevi on Friday, October 11, 2002 - 06:01 pm:

I think it is called a 'curl'

Yatir

By Alex Holyoake on Friday, October 11, 2002 - 07:34 pm:

Ta very much.

My applied maths teacher was insisting it was called delta, but its completely different (as well as meaning something completely different as well)

By Julian Pulman on Saturday, October 12, 2002 - 12:53 am:

No, curl is something entirely different.

In essence, it is delta, since d º dy. It's just really to remind you that a function could depend on more than one variable - hence finding dy/dx isn't really sufficient as you're only really finding how y varies as x changes.

I'm really with Geoff here, when I see y/x, I say ''partial y, partial x''. However, Arun is correct calling it ''del''.

Julian

By David Loeffler on Saturday, October 12, 2002 - 01:30 am:
Funny, I always thought 'del' was the vector gradient operator Ñ (a.k.a. 'nabla'). I tend to read y/x as 'partial y by partial x'.

David

By Yatir Halevi on Saturday, October 12, 2002 - 01:46 am:

then what is curl?

Yatir

By Julian Pulman on Saturday, October 12, 2002 - 09:47 am:

David, I think it is also, but a big del...e.g. the NRich formatting code calls them both Del.

Yatir, Curl F is the vector product of the gradient with the vector F.


Julian

By David Loeffler on Saturday, October 12, 2002 - 09:58 am:
Which is strange, as the NRICH formatting codes are effectively a watered-down version of TeX, and TeX uses
partial for . It may just be a convenience, pretending to the board's underlying scripts that one is the capital of the other in order to reduce the number of extra letters it has to think about.

David

By Julian Pulman on Saturday, October 12, 2002 - 01:06 pm:

Well, I had a little look around and stumbled across this webpage which uses

with an overline - dubbing it the ''del bar operator''; one might imply from this that a ''del bar'' without a bar is just simply a ''del'', hence is del. But also, this calls Ñ del too.
Julian
By David Loeffler on Saturday, October 12, 2002 - 02:03 pm:

Obviously the idea in my previous message is a load of rubbish then - sorry folks

David

By Tim Austin on Wednesday, October 16, 2002 - 02:30 pm:


I'm sure I have seen at least one reference in which the partial symbol is called "diff".
Tim

Editor: To summarise, has been described as bob, partial d, curly d, dabba, del, curl, delta, partial and diff.