Index notation

  • #1
Hello world,

Index notation is driving me crazy: why on Earth is ∂_i 1/r = -x_i/r^3 ?

I would expect it to be -x_i/r^2...

Thanks for commenting
 

Answers and Replies

  • #2
tiny-tim
Science Advisor
Homework Helper
25,832
251
welcome to pf!

hello ellocomateo! welcome to the world! :smile:

(try using the X2 and X2 buttons just above the Reply box :wink:)

∂r/∂x = … ? :wink:
 
  • #3
Oh, you mean chain rule and ∂r/∂i=xi/r
Thanks!
 

Related Threads on Index notation

  • Last Post
Replies
6
Views
764
  • Last Post
Replies
3
Views
2K
  • Last Post
Replies
2
Views
1K
  • Last Post
Replies
1
Views
28K
  • Last Post
Replies
3
Views
4K
  • Last Post
Replies
12
Views
2K
Replies
7
Views
4K
Replies
3
Views
1K
Replies
1
Views
2K
  • Last Post
Replies
1
Views
1K
Top