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

Rotation Matrices

  • Thread starter rrm74001
  • Start date
  • #1
1
0
[URGENT] Rotation Matrices

Homework Statement



http://e.imagehost.org/0661/Screen_shot_2010-03-09_at_12_37_44_AM.png [Broken]

Homework Equations



Rotation Matrix:
cos(theta) -sin(theta)
sin(theta) cos(theta)

The Attempt at a Solution



I understand 2a:

cos(pi/4) -sin(pi/4)
sin(pi/4) cos(pi/4)

But I am not sure what 2b is looking for. Please help?

Thank you in advance for your help!
 
Last edited by a moderator:

Answers and Replies

  • #2
ehild
Homework Helper
15,478
1,854


The matrix you wrote is a rotation matrix, which rotates a vector but leaves its length unchanged. You need a matrix which doubles the length as well. Try to find such one.


ehild
 
Last edited:

Related Threads on Rotation Matrices

  • Last Post
Replies
0
Views
894
  • Last Post
Replies
1
Views
479
  • Last Post
Replies
3
Views
6K
  • Last Post
Replies
7
Views
8K
  • Last Post
Replies
2
Views
2K
  • Last Post
Replies
9
Views
1K
  • Last Post
Replies
4
Views
1K
  • Last Post
Replies
9
Views
2K
  • Last Post
Replies
1
Views
1K
  • Last Post
Replies
6
Views
1K
Top