Is the zero vector always in the span of any set of vectors?

In summary, the conversation discusses the span of vectors and whether the zero vector is always included in the span. It is clarified that the zero vector will always be in the span of any set of vectors, as the weights of the linear combination can be zero. The confusion is due to the lack of explicit mention in the book.
  • #1
QuarkCharmer
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Homework Statement



Homework Equations



The Attempt at a Solution



It's not so much a homework problem as it is something I was wondering. Our book is horrible, and does not explicitly state that the zero vector is always in the span of two vectors. If I am understanding things right:

if v and u are vectors
[tex]span(v, u)[/tex]
is the collection of all points that can be reached via a linear combination of v and u. My reasoning is that if v is equal to u, then span{v,u} = span{v} = span{u}, which is essentially a line. However, it seems to me that in any space, R^2, R^3,...,R^n, the span{} of any n vectors will always go through the origin and thus, the zero vector will always be in that collection. Is that accurate?
 
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  • #2
Yes. Notice that if [itex]S[/itex] is a set and [itex]v \in S[/itex], then [itex]0 \cdot v = 0 \in \mathrm{Span}(S)[/itex].
 
  • #3
jgens said:
Yes. Notice that if [itex]S[/itex] is a set and [itex]v \in S[/itex], then [itex]0 \cdot v = 0 \in \mathrm{Span}(S)[/itex].

Yup, since the weights of the linear combination can be zero. Thanks, I just wanted clarification due to the books grey area. I know it seems obvious, but you would have to read this book to understand the confusion :smile:
 

FAQ: Is the zero vector always in the span of any set of vectors?

What is the difference between Span{} and the zero vector?

The Span{} is the set of all possible linear combinations of a given set of vectors, while the zero vector is a vector with all components equal to zero. In other words, the Span{} contains all possible directions and magnitudes that can be formed using the given vectors, while the zero vector is simply a point with no direction or magnitude.

What is the significance of the zero vector in Span{}?

The zero vector is significant because it is always included in the Span{} of any set of vectors. This is because it is possible to form a linear combination with a coefficient of zero, resulting in the zero vector. Therefore, the zero vector is always a part of the Span{} and is essential in defining the dimension of the Span{}.

Can the zero vector be a part of the basis of Span{}?

No, the zero vector cannot be a part of the basis of Span{}. The basis of Span{} is the smallest set of linearly independent vectors that can be used to form all other vectors in the Span{}. Since the zero vector is not a linearly independent vector (it can be formed by multiplying any vector by a coefficient of zero), it cannot be a part of the basis.

What is the geometric interpretation of Span{} and the zero vector?

The Span{} can be interpreted as the subspace formed by all possible combinations of the given vectors. The zero vector, in this context, represents the origin or the point of intersection of all the vectors in the Span{}. It can also be seen as the "center of mass" of the vectors in the Span{}.

How can Span{} and the zero vector be used in real-world applications?

Span{} and the zero vector have various applications in fields such as physics, engineering, and computer science. They are used to solve systems of linear equations, analyze vector spaces, and perform transformations in 3D graphics. In physics, they are used to study forces and motion. In engineering, they are used to analyze structures and design circuits. In computer science, they are used in machine learning and data analysis.

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