Linear algebra geometry of orthogonal decomposition

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SUMMARY

The discussion focuses on the orthogonal decomposition of the vector y = [4, 8, 1]^T into components within a subspace W and its complement. The user successfully decomposes y into y hat in W and z in W complement, identifying y hat as [2, 4, 5]^T and z as [2, 4, -4]^T. The user seeks clarification on the geometric relationship between the plane W in R^3 and the vectors y hat and z, emphasizing that the orthogonal projection of y onto W is a key concept in understanding this relationship.

PREREQUISITES
  • Understanding of vector spaces and subspaces in R^3
  • Familiarity with orthogonal projections and their properties
  • Knowledge of linear combinations and vector decomposition
  • Basic concepts of geometry related to planes and lines in three-dimensional space
NEXT STEPS
  • Study the concept of orthogonal projections in linear algebra
  • Learn about the geometric interpretation of vector decomposition in R^3
  • Explore the properties of subspaces and their complements
  • Investigate the relationship between lines and planes in three-dimensional geometry
USEFUL FOR

Students and educators in mathematics, particularly those studying linear algebra, geometry, and vector calculus, as well as anyone seeking to deepen their understanding of orthogonal decomposition and projections in R^3.

SpiffyEh
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Homework Statement


y=[4 8 1]^T u_1 = [2/3 1/3 2/3]^T u_2=[-2/3 2/3 1/3]^T

Part 1: Write y as the sum of a vector y hat in W and a vector z in W complement

Part 2: Describe the geometric relationship between the plane W in R^3 and the vectors y hat and z from the part above.


Homework Equations





The Attempt at a Solution


I got the first part I think.
y = [2 4 5]^T + [2 4 -4]^T

Part 2 is what I'm struggling with. I don't understand the relationship so I don't really know how to describe it. Can someone please help?
 
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Remember that a plane through the origin in [itex]\mathbb{R}^3[/itex] is completely determined by any line perpendicular to it. In other words, if you pick any line in 3-space, you're only going to be able to find one plane through the origin which is perpendicular to it.
 
I'm still confused. The only thing I really know about this is that ý is called the orthogonal projection of y onto W. But I don't understand what each of the components of y actually mean or do.
 

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