Why is there a free choice of variables when finding eigenvectors?

In summary, when finding eigenvectors, there is a free choice of variables to pick and you can substitute in any number to find an eigenvector. This is because for any value, the vector is an eigenvector. Additionally, the set of all eigenvectors form a subspace and if u and v are both eigenvectors, then so is au + bv for any scalars a and b.
  • #1
synkk
216
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BR1XZBL.png


Hi, I don't quite understand when finding eigenvectors there is usually a free choice of variables to pick, and you can sub in any number to find an eigenvector. Could anyone please explain how this works (and why you can sub in any number), as this usually comes up in vector problems with 3 variables also.
 
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  • #2
synkk said:
BR1XZBL.png


Hi, I don't quite understand when finding eigenvectors there is usually a free choice of variables to pick, and you can sub in any number to find an eigenvector. Could anyone please explain how this works (and why you can sub in any number), as this usually comes up in vector problems with 3 variables also.

For ANY value ##c \neq 0## the vector
[tex] \pmatrix{x\\y} = c \pmatrix{-5\\1} [/tex]
is an eigenvector. So, If I want, I can choose
[tex] \pmatrix{5000\\-1000}\text{ or } \pmatrix{-1/3 \\1/15}\text{ or } \cdots . [/tex]
 
  • #3
In fact, the set of all eigenvectors of liear transformation A, corresponding to a given eigenvalue, form a subspace.

If u and v are both eigenvectors corresponding to eigenvalue [itex]\lambda[/itex] then so is au+ bv for any scalars a and b:
[tex]A(au+ bv)= aA(u)+ bA(v)= a(\lambda u)+ b(\lambda v)= \lambda (au+ bv)[/tex].
 
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FAQ: Why is there a free choice of variables when finding eigenvectors?

What is the concept of "free choice of variables"?

The free choice of variables is a key principle in scientific research, particularly in the fields of physics and mathematics. It refers to the idea that the choice of variables used to describe a system or phenomenon should not affect the outcome or results of an experiment or calculation. In other words, the physical laws and equations that govern a system should not change depending on the variables chosen to represent it.

Why is the concept of "free choice of variables" important in scientific research?

The concept of free choice of variables is important because it allows scientists to analyze and understand complex systems or phenomena in a more efficient and accurate way. By choosing the most appropriate variables, researchers can simplify their experiments or calculations and obtain more meaningful results. It also ensures that the laws and equations used to describe a system are universal and not dependent on the variables chosen.

Can the concept of "free choice of variables" be applied to any scientific study?

Yes, the concept of free choice of variables can be applied to any scientific study where variables are used to represent a system or phenomenon. This includes fields such as biology, chemistry, and economics, in addition to physics and mathematics. However, the specific variables chosen may vary depending on the nature of the study and the specific questions being asked.

What are some potential limitations of the concept of "free choice of variables"?

One limitation of the concept of free choice of variables is that it assumes that all variables are equally valid and can be freely chosen. In reality, some variables may be more relevant or important than others, and choosing the wrong variables could lead to inaccurate or misleading results. Additionally, the choice of variables may be limited by the available data or resources.

How can scientists ensure that they are using the appropriate variables for their research?

To ensure that they are using the appropriate variables for their research, scientists should carefully consider the purpose of their study and the specific questions they are trying to answer. They should also consult with other experts in their field and conduct thorough literature reviews to determine which variables have been used in similar studies. Additionally, conducting sensitivity analyses and testing different sets of variables can help to identify the most relevant and accurate variables for a given study.

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