What is a Basis of a Vector Space and How to Find Another Basis?

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Homework Help Overview

The discussion revolves around finding an alternative basis for the vector space R4[z] of real polynomials of degree at most 4, given a standard basis. The original poster seeks to identify a basis B' that does not include scalar multiples of the standard basis vectors.

Discussion Character

  • Exploratory, Assumption checking

Approaches and Questions Raised

  • Participants discuss the validity of a proposed basis B' and question the inclusion of the zero vector. They explore the idea of using combinations of existing basis vectors with constants, such as adding 1 to elements of the standard basis.

Discussion Status

The conversation is ongoing, with participants providing hints and suggestions for constructing a valid basis. There is recognition of the constraints imposed by the degree of polynomials in R4[z], and some participants are questioning the feasibility of certain combinations.

Contextual Notes

Participants note that the zero vector cannot be included in a basis and that the highest degree for R4[z] is 4, which limits the options for constructing a new basis.

Coolster7
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Homework Statement



There is a standard basis, B = (1; z; z^2; z^3; z^4) where B is the basis of a R4[z] of real polynomials of at most degree 4.

I need to find another basis B' for R4[z] such that no scalar multiple of an
element in B appears as a basis vector in B' and also prove that this B' is a basis.

Can any help with this please?

Homework Equations





The Attempt at a Solution



I could only think to do a basis B'=(0,1,z,z^2,z^3) but no sure if this is correct.
 
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Coolster7 said:

Homework Statement



There is a standard basis, B = (1; z; z^2; z^3; z^4) where B is the basis of a R4[z] of real polynomials of at most degree 4.

I need to find another basis B' for R4[z] such that no scalar multiple of an
element in B appears as a basis vector in B' and also prove that this B' is a basis.

Can any help with this please?

Homework Equations





The Attempt at a Solution



I could only think to do a basis B'=(0,1,z,z^2,z^3) but no sure if this is correct.
No, it isn't correct. The 0 vector can never be a vector in a basis for a vector space.

Here's a hint: the function 1 + z is not a linear multiple of any of the vectors in B, right?
 
Mark44 said:
No, it isn't correct. The 0 vector can never be a vector in a basis for a vector space.

Here's a hint: the function 1 + z is not a linear multiple of any of the vectors in B, right?

So you could have B' = (1+z, 1+z^2, 1+z^3, 1+z^4, 1+z^5) for example or would this not work because the highest degree for R4[z] is 4?

Thanks for your reply.
 
Right, you can't have 1 + z5. Can't you think of any other combinations besides adding 1 to another vector in the basis?
 

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