What are the components of the vector d²r in relation to dr?

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The discussion centers on the components of the vector d²r in relation to dr, where dr is defined as (dx, dy, dz). Participants debate whether the correct form for d²r is (d²x, d²y, d²z) or (dy^dz, dz^dx, dx^dy). Some clarify that d²r can be understood as the second derivative of the position vector, linking it to the concept of differential forms. However, one contributor notes that the expression d²r is ambiguous and suggests that it may not have practical utility. The conversation highlights confusion regarding the mathematical representation of second derivatives in vector calculus.
Jhenrique
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If dr = (dx, dy, dz) so, which is the correct form for d²r? Is (d²x, d²y, d²z) or (dy^dz, dz^dx, dx^dy) ?
 
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what isr ? :confused:
 
tiny-tim said:
what isr ? :confused:

you must be joking
 
tiny-tim said:
what isr ? :confused:

Jhenrique said:
you must be joking

Seems like a reasonable question to me.
 
I imagine he's referring to the "numerator" of a second derivative such as ##\frac{d^2 \vec{r}}{dt^2}## in analogy with his identification of the differential form ##d\vec{r}## with the "numerator" of a first derivative.
 
MuIotaTau said:
I imagine he's referring to the "numerator" of a second derivative such as ##\frac{d^2 \vec{r}}{dt^2}## in analogy with his identification of the differential form ##d\vec{r}## with the "numerator" of a first derivative.

Is this even. No doubts.
 
Jhenrique said:
If dr = (dx, dy, dz) so, which is the correct form for d²r? Is (d²x, d²y, d²z) or (dy^dz, dz^dx, dx^dy) ?

I've seen d²r used as an alternative to dS in surface integrals.
 
Jhenrique said:
If dr = (dx, dy, dz) so, which is the correct form for d²r? Is (d²x, d²y, d²z) or (dy^dz, dz^dx, dx^dy) ?

The correct form of ##\mathrm{d}^2r=\mathrm{d}(\mathrm{d}r)## is 0. Your question is incredibly ambiguous, and I wouldn't expect anyone to understand what you're asking without clarification.
 
Mandelbroth said:
The correct form of ##\mathrm{d}^2r=\mathrm{d}(\mathrm{d}r)## is 0.

This is theoretical identity that in the practice is useless.

I just asking which are the components of the vector d²r.

The components of the vector r is (x, y, z);

of dr is (dx, dy, dz)

But, I have doubt if the components of vector d²r is (d²x, d²y, d²z) or (dydz, dzdx, dxdy) or other...
 

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