Is W1\cap W2 a Vector Space if dim(W1)=1 and dim(W2)=2?

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Homework Help Overview

The discussion revolves around the intersection of two vector spaces, W1 and W2, within the context of F^3, where the dimensions of W1 and W2 are given as 1 and 2, respectively. Participants are exploring whether the intersection W1 ∩ W2 can be considered a vector space, particularly questioning the conditions under which it may or may not be the zero space.

Discussion Character

  • Exploratory, Assumption checking, Conceptual clarification

Approaches and Questions Raised

  • Participants are examining the implications of the dimensions of W1 and W2 on their intersection, questioning scenarios where W2 might include W1, and discussing the conditions that would affect the nature of their intersection. There is also mention of a potential direct sum and the requirement for W1 + W2 to equal F^3.

Discussion Status

The discussion is active, with participants providing examples and counterexamples to illustrate their points. Some guidance has been offered regarding the implications of dimensionality and the conditions under which the intersection may not be trivial. Multiple interpretations of the problem are being explored without reaching a consensus.

Contextual Notes

There are no explicit constraints mentioned beyond the dimensions of the subspaces, leading to various interpretations of the intersection's properties. The discussion hints at the importance of additional conditions, such as whether W1 + W2 equals F^3, which could influence the outcome.

transgalactic
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there are two W1 and W2 of F^3 space
dim(W1)=1
dim(W2)=2

prove or desprove that:

W1\cap W2={0} is the vector space
??

there could be a case where W2 includes W1 then there intersection is not the 0 space
correct??
 
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If there are no other constraints on the problem then yeah.

Take a plane going through the origin and a line contained on that plane in R^3.

That seems like a silly problem though. Do you know anything else like

W1+W2 = W3 (direct sum?)
 
can you give an actual example
??
 
I am just saying your counterexample (or one like it) works as long as there are no other restrictions on the problem.

If we require that W1+W2 = F^3, then it is true, because one space cannot contain the other.
 
if W2 include W1
and we have another subspace W3
which
dim W3=1
then dimW2+dimW3=3

what is the problem in that??
 
Nothing, that's tenable.
 

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