• Support PF! Buy your school textbooks, materials and every day products Here!

Calculus question

  • Thread starter raintrek
  • Start date
  • #1
75
0

Homework Statement



I have the following expression:

[tex]cos\theta = \frac{\vec{a}\cdot \vec{b}}{ab}[/tex]
(this is simply taken from a dot product rule for two vectors)

However I need to find [tex]\nabla_{\vec{r}i} \theta[/tex]

Is there a way I can do it without involving differentials of arccos and the like? I can't use a small angle approximation as these angles are around 60-100 degrees. Any suggestions appreciated!
 

Answers and Replies

  • #2
1,357
0
Please confirm: You want to find the gradient of theta?
 
  • #3
75
0
It's ok, I read the question wrong. Sorry about that folks
 

Related Threads for: Calculus question

  • Last Post
Replies
2
Views
1K
  • Last Post
Replies
2
Views
2K
  • Last Post
Replies
2
Views
1K
  • Last Post
Replies
4
Views
1K
  • Last Post
Replies
2
Views
5K
  • Last Post
Replies
3
Views
1K
  • Last Post
Replies
1
Views
1K
  • Last Post
Replies
4
Views
2K
Top