science | February 14, 2026

What is subspace in linear algebra?

What is subspace in linear algebra?

A subspace is a term from linear algebra. Members of a subspace are all vectors, and they all have the same dimensions. For instance, a subspace of R^3 could be a plane which would be defined by two independent 3D vectors. These vectors need to follow certain rules.

How do you define a subspace?

A subspace is a vector space that is contained within another vector space. So every subspace is a vector space in its own right, but it is also defined relative to some other (larger) vector space.

What are the three properties of a subspace?

What is a vector subspace?

  • Zero vector property. This property states that any set of vectors considered as a subspace in R n R^{n} Rn will contain the zero vector.
  • Closed under addition property.
  • Closed under scalar multiplication property.

How do you determine if something is a subspace?

In other words, to test if a set is a subspace of a Vector Space, you only need to check if it closed under addition and scalar multiplication. Easy! ex. Test whether or not the plane 2x + 4y + 3z = 0 is a subspace of R3.

Is a subspace linearly independent?

If a set of vectors are in a subspace H of a vector space V, and the vectors are linearly independent in V, then they are also linearly independent in H. This implies that the dimension of H is less than or equal to the dimension of V.

Is there a symbol for subspace?

I’ve seen U≤V and U being used to denote subspaces and proper subspaces respectively, but these aren’t common enough to be used without explicity specifying their meaning first. Another way that at least one text book I’ve red used was to reserve certain letters for certain types of things.

What does subspace of R3 mean?

A subset of R3 is a subspace if it is closed under addition and scalar multiplication. It is easy to check that S2 is closed under addition and scalar multiplication. Alternatively, S2 is a subspace of R3 since it is the null-space of a linear functional ℓ : R3 → R given by ℓ(x, y, z) = x + y − z, (x, y, z) ∈ R3.

How many subspaces does R3 have?

It is clear that every two dimensional plane in R3 is a subspace of R3. Since there are infinitely many two dimensional planes in R3, it follows that there are infinitely many subspaces in R3.

Is subspace linearly dependent?