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CompuChip

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HallsofIvy

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First, it is not a "letter" in the English alphabet. It is a special symbol. I, myself, have never heard it called "del". To me "del" is the vector operator, "nabla", [itex]\nabla[/itex]. If f(x, y, z) is a real valued function of x, y, and z (Cartesian coordinates) then "del f" (also called "grad f") is the vector function

[tex]\nabla f= \frac{\partial f}{\partial x}\vec{i}+ \frac{\partial f}{\partial y}\vec{j}+ \frac{\partial f}{\partial z}\vec{k}[/tex]

Similarly, I have heard "div v" called "del dot v" and "curl v" called "del cross v" for vector function v, though I would not consider any of those as formal as "grad", "div", or "curl".

I have, though, heard [itex]\partial [/itex] called "curly d". The LaTex code for it is "\partial".

[tex]\nabla f= \frac{\partial f}{\partial x}\vec{i}+ \frac{\partial f}{\partial y}\vec{j}+ \frac{\partial f}{\partial z}\vec{k}[/tex]

Similarly, I have heard "div v" called "del dot v" and "curl v" called "del cross v" for vector function v, though I would not consider any of those as formal as "grad", "div", or "curl".

I have, though, heard [itex]\partial [/itex] called "curly d". The LaTex code for it is "\partial".

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tiny-tim

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Yes, ∂ isn't an English letter or even a Greek letter like ∑ or π, it's just a symbol.

I believe a lot of people pronounce it "dabba", but I just pronounce it "d" (though I

(and I also have never heard it pronounced "del", that's for ∇)

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CompuChip

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I, myself, have never heard it called "del". To me "del" is the vector operator, "nabla", [itex]\nabla[/itex].

Whoops, you are so right.

I meant to say "dau" ([dow]).

* deeply ashamed *

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∂ is a letter of Cyrillic alphabet, right? I remember my teacher said it in a lesson.

Anyway, I read:

[tex]\frac{\partial f}{\partial x}[/tex]

as "de" f over "de" x

Anyway, I read:

[tex]\frac{\partial f}{\partial x}[/tex]

as "de" f over "de" x

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Del,

Dau,

D,

Partial.

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Mark44

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Sort of. In Russian, the cursive form of lower case Д is sometimes written as ∂, and sometimes as g. That's always been a little confusing to me. This wike article, http://en.wikipedia.org/wiki/Cyrillic_alphabet, has some good information.∂ is a letter of Cyrillic alphabet, right?

I remember my teacher said it in a lesson.

Anyway, I read:

[tex]\frac{\partial f}{\partial x}[/tex]

as "de" f over "de" x

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To my knowledge, we say "partial". That's what I've always heard and was told a while ago.

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Mark44

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∂ is a letter of Cyrillic alphabet, right? I remember my teacher said it in a lesson.

Anyway, I read:

[tex]\frac{\partial f}{\partial x}[/tex]

as "de" f over "de" x

If you say "dee" f over "dee" x, someone listening would likely interpret this as the ordinary derivative instead of a partial derivative. There have been a number of times where I was helping someone with calculus over the phone. In such cases you have to be more clear than when you can see the work.

Yeah, me, too. I always pronounce this as "partial of f with respect to x."To my knowledge, we say "partial". That's what I've always heard and was told a while ago.

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If you say "dee" f over "dee" x, someone listening would likely interpret this as the ordinary derivative instead of a partial derivative. There have been a number of times where I was helping someone with calculus over the phone. In such cases you have to be more clear than when you can see the work.

Yes you're right. Here, we use the name of [tex]\partial[/tex], that is dɛ in IPA.

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Nabeshin

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[tex]\partial_x = \frac{\partial}{\partial x}[/tex]

Read as, obviously, partial x. Insert "of" if when operating on something you think it sounds weird to omit it.

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