Proofs of subspaces in R^n (intersection, sums, etc.)

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SUMMARY

The discussion focuses on proving properties of subspaces E and F in R^n, specifically regarding their intersection and sum. It establishes that if the intersection EnF equals the zero vector, then the dimension of the sum E+F equals the sum of the dimensions of E and F. Additionally, it confirms that both the intersection and sum of subspaces are themselves subspaces of R^n. Key concepts include linear independence and closure under addition and subtraction.

PREREQUISITES
  • Understanding of linear independence in vector spaces
  • Knowledge of subspace properties in R^n
  • Familiarity with dimension theory in linear algebra
  • Concept of closure under vector addition and scalar multiplication
NEXT STEPS
  • Study the proof of the subspace theorem in linear algebra
  • Learn about the properties of linear transformations and their relation to subspaces
  • Explore the concept of basis and dimension in vector spaces
  • Investigate the implications of the rank-nullity theorem in R^n
USEFUL FOR

Students of linear algebra, mathematicians, and educators looking to deepen their understanding of vector spaces and subspace properties in R^n.

shellizle
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Homework Statement


Let E and F be two subspaces of R^n. Prove the following statements:

(n means "intersection")
  1. If EnF = {0}, {u1, u2, ..., uk} is a linearly independent set of vectors of E and {v1, v2,...vk} is a linearly independent set of vectors
    Note: Above zero denotes the zero vector in R^n
  2. EnF = {u, such that u is in E, and u is in F} is a subspace of R^n
  3. E+F = {w=u+v, u is in E, v is in F} is a subspace of R^n
  4. If EnF={0} then dim(E+F)=dim(E)+dim(F)
 
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shellizle said:

Homework Statement


Let E and F be two subspaces of R^n. Prove the following statements:

(n means "intersection")
  1. If EnF = {0}, {u1, u2, ..., uk} is a linearly independent set of vectors of E and {v1, v2,...vk} is a linearly independent set of vectors
    Note: Above zero denotes the zero vector in R^n
  2. EnF = {u, such that u is in E, and u is in F} is a subspace of R^n
  3. E+F = {w=u+v, u is in E, v is in F} is a subspace of R^n
  4. If EnF={0} then dim(E+F)=dim(E)+dim(F)
for the intersection questions, think about closure under addition (and subtraction)
for the dimension question, think about what would happen if vectors "overlapped" in two spaces..
 

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