Can Four Vectors in R3 Have Any Three Linearly Independent?

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SUMMARY

In R3, it is impossible to have a set of four vectors where any three of them are linearly independent. The discussion illustrates this by presenting three linearly independent vectors: v1 = (0,0,1), v2 = (0,-2,2), and v3 = (1,-2,1), which can be verified using Gaussian Elimination. The challenge arises when attempting to add a fourth vector, as it must not be parallel to any of the existing three, which contradicts the dimensionality of R3. Thus, the conclusion is that while three vectors can be linearly independent, a fourth vector cannot maintain this property in R3.

PREREQUISITES
  • Understanding of linear independence in vector spaces
  • Familiarity with Gaussian Elimination for matrix row reduction
  • Knowledge of vector representation in R3
  • Concept of dimensionality in linear algebra
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  • Study the concept of linear independence in higher dimensions, such as R4
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Students and professionals in mathematics, particularly those studying linear algebra, vector spaces, and geometric interpretations of vectors. This discussion is also beneficial for educators teaching concepts of linear independence and dimensionality.

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Q: Is there a set of four vectors in R3, any three of which form a linearly independent set? Prove.

Okay so i know what linearly independent is, i have 3 vectors which are linearly independent but I can't find a fourth vector to satisfy the need of the questions like:

vectors: v1 = (0,0,1), v2 = (0,-2,2), v3 = (1,-2,1) these three vectors are linearly independent when you use Guassian Elimination on the matrix:

| 0 0 1 |
| 0 -2 -2 |
| 1 2 1 |

you get all the scalars equal to 0. So this satisfy the part where "any three of which form a linearly independent set" is written but the first part says need 4 vectors.
Any suggestions?
 
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Surely come up with a set of three vectors in R3 that form a linearly independent set, right? Now, just add 4th vector that is id to all of them. This is eqivilent to finding a vector that is not parallel to any of the other three.

For example, if we were to ask for a set of 3 vectors in R2 such that any two of them form a linearly independent set, I would say v1=(1,0) v2=(0,1) and v3=(1,1).
 

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