Why do we use ∂ in partial differentiation for multiple variables?

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Voq
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Why we write differently d in partial derivation differentiation? Is it because of several variables?

Edited by mentor -- the action of finding a derivative is called differentiation.
 
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Voq said:
Why we write differently d in partial derivation? Is it because of several variables?
If you write it with the same symbol, make sure you will always add the direction. In this case you could write ##D_{e_i}## for the partial derivatives along the ##i-##th coordinate, ##D_v## for a directional derivative, and ##D## for the total differential or Jacobi matrix. Note, that ##D## is an operator here, which has three degrees of freedom: directions ##v##, functions ##f## and evaluation points ##x_0\, : \, D_v(f)(x_0)##. In this case it's better to avoid all other notations as ##\frac{d}{dx}## or ##\nabla f## or ##\operatorname{grad} f\,,## too.
 
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Voq said:
We use small delta for partial differentiation.
No, it's actually a different character, one for which I've never seen a name.

Here are upper- and lowercase deltas: ##\Delta## and ##\delta##.
Here is the character used for partial derivatives: ##\partial##
Here is the partial of f with respect to x, using Leibniz notation: ##\frac{\partial f}{\partial x}##.
Here is the unrendered LaTeX for the above: ##\frac{\partial f}{\partial x}##.
 
Mark44 said:
No, it's actually a different character, one for which I've never seen a name.

Here are upper- and lowercase deltas: ##\Delta## and ##\delta##.
Here is the character used for partial derivatives: ##\partial##
Here is the partial of f with respect to x, using Leibniz notation: ##\frac{\partial f}{\partial x}##.
Here is the unrendered LaTeX for the above: ##\frac{\partial f}{\partial x}##.
One can also mention that the lowercase delta is sometimes used for other types of derivatives. But those are probably best left out for now.
 
Found this on wiki.
The character ∂ is a stylized d mainly used as a mathematical symbol to denote a partial derivative such as
b3c50962e268174c3dd439b5650b373db214c86e
(read as "the partial derivative of z with respect to x").
The symbol is referred to as "del" (not to be confused with ∇, also known as "del"), "dee", "partial dee", "partial" (especially in LaTeX), "round d","curly dee", "doh", "die" or "dabba".