Show that this system is not a vector space

In summary, the conversation discusses a homework problem involving showing that a system S is not a vector space by disproving one of the axioms with the usual rules for addition and multiplication by a scalar in ℝ3. The system S is defined as {x(ℝ3):2x1+3x32-4x23=0}, with x being a vector in ℝ3. The problem was initially misstated, but the issue was resolved and the problem was solved successfully.
  • #1
charmedbeauty
271
0

Homework Statement



Show that the system S is not a vector space by showing one of the axioms is not satisfied with the usual rules for addition and multiplication by a scalar in ℝ3

S={x(ℝ3):2x1+3x32-4x23=0}


Homework Equations





The Attempt at a Solution



The subscripts for the x's are strange I think but I guess that shouldn't make a difference.

But I'm really stuck on this I think it should be fairly easy though.

but for example if I try closure under scalar multiplication

or closure under addition I keep coming to a dead end because I don't know the value of the x's.

ie λ[2x1+3x32-4x23]=λ[0]

...λ[2x1+3x32-4x23]=0

I think I just need a hint in the right direction. Thanks
 
Physics news on Phys.org
  • #2
The way I see it, you have one major problem- what you are trying to prove is not true!

Now, please tell us the exact wording of the problem. I suspect you are misstating it.
 
  • #3
charmedbeauty said:

Homework Statement



Show that the system S is not a vector space by showing one of the axioms is not satisfied with the usual rules for addition and multiplication by a scalar in ℝ3

S={x(ℝ3):2x1+3x32-4x23=0}

I don't understand what you have above. Presumably x is a vector in R3. Why are there two subscripts on some of the variables in your equation?
 
  • #4
HallsofIvy said:
The way I see it, you have one major problem- what you are trying to prove is not true!

Now, please tell us the exact wording of the problem. I suspect you are misstating it.

Mark44 said:
I don't understand what you have above. Presumably x is a vector in R3. Why are there two subscripts on some of the variables in your equation?

Ok sorry I did mistake the problem.

it really should have said 2x1+3x32-4x32

I mistakenly read it as it was not typed out ver well and it appeared to look like weird subscript notation.

and I solved it no problems

Thanks for letting me know!
 

1. What is a vector space?

A vector space is a mathematical structure that contains a set of objects called vectors and follows a set of rules, known as axioms, that allow for operations such as addition and scalar multiplication to be performed on these vectors. These rules must be satisfied for a system to be considered a vector space.

2. What are the axioms of a vector space?

The axioms of a vector space include closure under addition and scalar multiplication, commutativity and associativity of addition, existence of an additive identity element, existence of additive inverses for all vectors, and distributivity of scalar multiplication over addition.

3. How do you show that a system is not a vector space?

To show that a system is not a vector space, we need to find at least one instance where one of the axioms is not satisfied. This would prove that the system does not follow all the rules of a vector space and therefore, cannot be considered one.

4. Can a system be partially a vector space?

No, a system must fulfill all the axioms of a vector space to be considered one. If even one axiom is not satisfied, the system cannot be considered a vector space.

5. Why is it important to determine if a system is a vector space or not?

Determining if a system is a vector space is important in many fields of science, particularly in linear algebra and physics. It allows us to understand the fundamental properties of a system and use mathematical tools to solve problems and make predictions based on these properties.

Similar threads

  • Differential Geometry
Replies
3
Views
1K
  • Calculus and Beyond Homework Help
Replies
0
Views
441
  • Calculus and Beyond Homework Help
Replies
2
Views
1K
  • Calculus and Beyond Homework Help
Replies
3
Views
2K
  • Calculus and Beyond Homework Help
Replies
9
Views
3K
  • Calculus and Beyond Homework Help
Replies
2
Views
1K
  • Calculus and Beyond Homework Help
Replies
12
Views
2K
  • Calculus and Beyond Homework Help
Replies
9
Views
1K
  • Calculus and Beyond Homework Help
2
Replies
43
Views
3K
  • Calculus and Beyond Homework Help
Replies
7
Views
1K
Back
Top