Do the vectors u = (5,1,3) and v = (2,3,6) belong to span(S)?

Click For Summary

Homework Help Overview

The problem involves determining whether the vectors u = (5,1,3) and v = (2,3,6) belong to the span of the set S = [(1,-1,3), (-1,3,-7), (2,1,0)]. The discussion centers around the concept of span in linear algebra.

Discussion Character

  • Conceptual clarification, Problem interpretation, Assumption checking

Approaches and Questions Raised

  • Participants discuss the definition of span and the conditions under which a vector belongs to a span. There is an exploration of linear combinations of the vectors in S and how they relate to u and v. Questions arise regarding the correct interpretation of the span concept.

Discussion Status

Some participants provide guidance on how to approach the problem by suggesting the use of matrix forms and systems of equations to check for linear dependence or independence. There is acknowledgment of the need to analyze both vectors u and v separately.

Contextual Notes

Participants note the potential confusion regarding the definitions and relationships between the vectors and the span. There is mention of formatting issues with representing vectors in matrix form.

phys2
Messages
21
Reaction score
0

Homework Statement



The problem is : Let S = [ (1,-1,3) , (-1,3, -7) , (2,1,0) ]. Do the vectors u = (5,1,3) and v = (2,3,6) belong to span(S)


Homework Equations





The Attempt at a Solution



So span means that I could take linear combinations of u and v and they should end up giving (1,-1,3) , (-1,3,-7) and (2,1,0). Right?

I could take x [5 1 3 ] + y [ 2 3 6 ] = [1 -1 3] or [-1 3 -7 ] or [2 1 0 ] (btw i meant to write [ 5 1 3] as a column matrix but I am not sure of how to using Latex. So anyway, is what I am trying to do correct? Is that what it means for the vectors to span S?

Thanks
 
Physics news on Phys.org
phys2 said:

Homework Statement



The problem is : Let S = [ (1,-1,3) , (-1,3, -7) , (2,1,0) ]. Do the vectors u = (5,1,3) and v = (2,3,6) belong to span(S)


Homework Equations





The Attempt at a Solution



So span means that I could take linear combinations of u and v and they should end up giving (1,-1,3) , (-1,3,-7) and (2,1,0). Right?
No, it's the other way around.

Span(S) is the set of all linear combinations of the vectors in S. u is in Span(S) if there are constants a, b, and c for which a(1, -1, 3) + b(-1, 3, -7) + c(2, 1, 0) = u.

Similarly for v.
phys2 said:
I could take x [5 1 3 ] + y [ 2 3 6 ] = [1 -1 3] or [-1 3 -7 ] or [2 1 0 ] (btw i meant to write [ 5 1 3] as a column matrix but I am not sure of how to using Latex. So anyway, is what I am trying to do correct? Is that what it means for the vectors to span S?

Thanks
 
Put your vectors from S into matrix form, augmenting them with either u or v ( You'll have to do both at some point so pick one at a time ).

Solve the corresponding system and check if the following system is linearly independent or dependent.

If the system is dependent for your choice of u or v, then you can conclude that the vector is not in the span of your set. Otherwise if your system is independent, you can exhibit a unique solution for your system implying that your vector IS in the span of your set.
 
No, it's the other way around.

Span(S) is the set of all linear combinations of the vectors in S. u is in Span(S) if there are constants a, b, and c for which a(1, -1, 3) + b(-1, 3, -7) + c(2, 1, 0) = u.

Similarly for v.

Ahh I see thanks

Solve the corresponding system and check if the following system is linearly independent or dependent.

Yes, it works out...thanks
 

Similar threads

Replies
15
Views
3K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 5 ·
Replies
5
Views
7K
Replies
8
Views
2K
Replies
4
Views
2K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 4 ·
Replies
4
Views
2K