Should it be upside or downside

  • #1
MathematicalPhysicist
Gold Member
4,289
203

Main Question or Discussion Point

how does the triangle symbol in Helmholtz Equation should be?
is it like the attach file in here.
 
Last edited:

Answers and Replies

  • #2
MathematicalPhysicist
Gold Member
4,289
203
or like this attach file.

btw, can you attach more then one file in here?
 
Last edited:
  • #3
248
0
If I remember correctly, then they are both the same. nabla squared is sometimes denoted as a triangle with the sharp side up.

So:

[tex]\nabla^2 \equiv \Delta[/tex]
 
  • #4
Njorl
Science Advisor
258
10
I've always seen it point down.

Njorl
 
  • #5
591
0
I also usually see [itex]\nabla^2[/itex]. But [itex]\Delta[/itex] is perfectly valid.

Personally I prefer [itex]\nabla^2[/itex]. It makes it more clear what operation you're actually performing. Plus it help avoid defining a new symbol for every single mathematical operation. And [itex]\Delta[/itex] is already used enough anyway.

In the Helmholtz equation in particular [itex]\nabla^2[/itex] looks better.
[itex]\nabla^2\psi+k^2\psi=0[/itex] is more symmetric.
 
  • #6
HallsofIvy
Science Advisor
Homework Helper
41,833
956
loop quantum gravity: note well it is [tex]\nabla^2[/tex] and [tex] \Delta[/tex] that are the same not [tex]\nabla [/tex]and [tex] \Delta[/tex]!
 

Related Threads on Should it be upside or downside

Replies
6
Views
535
Replies
8
Views
2K
Replies
2
Views
1K
  • Last Post
Replies
1
Views
866
  • Last Post
Replies
1
Views
1K
  • Last Post
Replies
4
Views
1K
  • Last Post
Replies
14
Views
2K
Replies
2
Views
3K
Replies
2
Views
1K
Replies
2
Views
1K
Top