Essential Vocabulary

Here is a link to a list of these terms on Quizlet

Basis

A set of vectors is called a basis of (or a basis of a subspace of ) provided that

(a)
(or )
(b)
is linearly independent.

Closed under addition

A set is said to be closed under addition if for each element and the sum is also in .

Closed under scalar multiplication

A set is said to be closed under scalar multiplication if for each element and for each scalar the product is also in .

Column space of a matrix

Let be an matrix. The column space of , denoted by , is the subspace of spanned by the columns of .

Coordinate vector with respect to a basis

Let be an ordered basis. Then the coordinate vector is the column vector such that .

Dimension

Let be a subspace of . The dimension of is the number, , of elements in any basis of . We write

Null space of a matrix

Let be an matrix. The null space of , denoted by , is the set of all vectors in such that . It is a subspace of .

Nullity of a matrix

Let be a matrix. The dimension of the null space of is called the nullity of .

Ordered basis

A basis in which the elements appear in a specific fixed order. Establishing an order is necessary because a coordinate vector with respect to a given basis relies on the order in which the basis elements appear.

Rank of a matrix

Let be a matrix. The dimension of the row space of is called the rank of .

Rank-Nullity theorem

Let be an matrix. Then

Row space of a matrix

Let be an matrix. The row space of , denoted by , is the subspace of spanned by the rows of .

Subspace

Suppose that is a nonempty subset of that is closed under addition and closed under scalar multiplication. Then is a subspace of .

2024-09-06 02:11:46