Essential Vocabulary

Coordinate vector

Let be a vector space, and let be a basis for . If , then the vector in whose components are the coefficients is said to be the coordinate vector for with respect to . We denote the coordinate vector by and write:

Finite-dimensional vector space

A vector space is said to be finite-dimensional if it is spanned by finitely many vectors.

Isomorphism

Let and be vector spaces. If there exists an invertible linear transformation we say that and are isomorphic and write . The invertible linear transformation is called an isomorphism.

Matrix of a linear transformation

Let and be finite-dimensional vector spaces with ordered bases and , respectively. Suppose is a linear transformation. Then for all vectors in .

Matrix is called the matrix of with respect to ordered bases and .

One-to-one linear transformation

A linear transformation is one-to-one if

Onto linear transformation

A linear transformation is onto if for every element of , there exists an element of such that .

Subspace

A nonempty subset of a vector space is called a subspace of , provided that is itself a vector space when given the same addition and scalar multiplication as .

Vector Space

Let be a nonempty set. Suppose that elements of can be added together and multiplied by scalars. The set , together with operations of addition and scalar multiplication, is called a vector space provided that

  • is closed under addition
  • is closed under scalar multiplication

and the following properties hold for , and in and scalars and :

(a)
Commutative Property of Addition:
(b)
Associative Property of Addition:
(c)
Existence of Additive Identity:
(d)
Existence of Additive Inverse:
(e)
Distributive Property over Vector Addition:
(f)
Distributive Property over Scalar Addition:
(g)
Associative Property for Scalar Multiplication:
(h)
Multiplication by :

We will refer to elements of as vectors.

Note that definitions of span, linear independence, basis, and dimension are analogous to those for subspaces of .

2024-09-06 02:10:02