Vector Addition Question: find angle (A+B & A-B)

  • #1
49
1
Member has been warned to show more of their own effort.

Homework Statement


Two vectors A and B have precisely equal magnitudes. For the magnitude of A + B to be 65 times greater than the magnitude of A - B, what must be the angle between them?

Homework Equations




The Attempt at a Solution


I tried using the dot product and solving for the angle but i dont know if my math was right. I keep getting a relatively small angle which I know is around the right answer but its still off somehow. Please help!!
 

Answers and Replies

  • #2
167
45
Try something like A = a + jb, where a and b are the components of A.
 
  • #3
49
1
Try something like A = a + jb, where a and b are the components of A.

can you elborate? im not quite sure what you mean
 
  • #4
haruspex
Science Advisor
Homework Helper
Insights Author
Gold Member
37,986
7,702
I tried using the dot product and solving for the angle but i dont know if my math was right. I keep getting a relatively small angle which I know is around the right answer but its still off somehow.
Please post your working. We can rarely tell where you are going wrong from a rough outline.
 

Related Threads on Vector Addition Question: find angle (A+B & A-B)

  • Last Post
Replies
8
Views
3K
Replies
2
Views
2K
  • Last Post
Replies
4
Views
5K
  • Last Post
Replies
10
Views
4K
Replies
13
Views
807
Replies
3
Views
3K
  • Last Post
Replies
5
Views
2K
  • Last Post
Replies
2
Views
2K
  • Last Post
Replies
13
Views
22K
Top