3-dimensional Vector problem.

  • Thread starter linuxux
  • Start date
  • #1
133
0

Homework Statement



Given the vectors: V1=(3,1,2) and V2=(2,2,-1), find the set of vectors which are coplanar with V1 and V2 and also perpendicular to V3=(-2,1,1). Then Find the members of this set which have length 2-Root-11

Homework Equations



Dot and cross product

The Attempt at a Solution



well, a set of vectors coplanar to v1 and v2 would be V = (x,y,z) = (x',y',z') + rV1 +sV2
and a vector perpendicular to v3 in the set of vectors coplanar with v1 and v2 is: V X V3.
But what do i do with the 2-root-11?
 
Last edited:

Answers and Replies

  • #2
Dick
Science Advisor
Homework Helper
26,260
619
VxV3 is not necessarily coplanar with V1 and V2. It's just perpendicular to whatever V you choose. Can you think of an expression using a dot product to express V perpendicular to V3? Finally the length of a vector is sqrt(v.v), right?
 
  • #3
133
0
okay, ill try it that way...
 

Related Threads on 3-dimensional Vector problem.

  • Last Post
Replies
4
Views
2K
  • Last Post
Replies
0
Views
1K
Replies
9
Views
1K
Replies
1
Views
1K
  • Last Post
Replies
4
Views
2K
  • Last Post
Replies
3
Views
13K
  • Last Post
Replies
2
Views
3K
Replies
0
Views
2K
Replies
8
Views
3K
Replies
1
Views
2K
Top