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Partial derivatives operator

-MFra-
21-Topaz II

Partial derivatives operator

Hi,

How can I modify the operator so that it works correctly and not as shown in the figure? In the image what I would like is marked in red:

symbolic.jpg

I used a letter linked to the sword symbol (but I could have used others) because when it is used as an argument of a function in a reference file, it is sure that, in the calling program (s) (in which I will be careful not to use that symbol, linked to the sword symbol), no conflicts arise.

1 ACCEPTED SOLUTION

Accepted Solutions
LucMeekes
23-Emerald III
(To:-MFra-)

5 REPLIES 5
LucMeekes
23-Emerald III
(To:-MFra-)

LucMeekes_0-1615197698614.png

Success!

Luc

 

-MFra-
21-Topaz II
(To:LucMeekes)

I would need something more than previously said. For example, use those operators in the rotor calculation as in the figure:

symbolic 1.jpg,

is it possible?

LucMeekes
23-Emerald III
(To:-MFra-)

I'm afraid not. And I doubt if the operation, defined through the determinant, is mathematically correct.

Anyway, if all items of the 3x3 matrix are just symbols, this is what you get:

LucMeekes_0-1615237182162.png

So it looks great, until you look closer. In the first term of i.x, the partial derivative to y is not applied to V.z, but simply multiplied with it.

With the partial derivative 'operators' (in fact they're defined as functions) defined you're getting undefined items.

LucMeekes_1-1615237356871.png

Success!
Luc

-MFra-
21-Topaz II
(To:LucMeekes)

in fact that is a mnemonic rule for calculating the rotor. It is also given by the vector product between the vector of the operators and the given vector.

rot.jpg

which also makes no sense.

Obviously, your displayed result does not make sense as well.

Fred_Kohlhepp
23-Emerald I
(To:-MFra-)

Are you aware that the del symbol is the functional gradient operator?  In Mathcad 15 (not Prime) you get it with cntrl+shift+G, you can subscript which variables you want to take the derivative of.  There were a few old posts . ..

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