Linear algebra

Vector

A vector is an element of a vector space. In coordinates it can be represented by an ordered list of numbers with rules for addition and scalar multiplication.

Ask the Linear algebra assistant1 min read · Updated September 9, 2026

Definition

A vector is an element of a vector space. In coordinates it can be represented by an ordered list of numbers with rules for addition and scalar multiplication.

Intuition

Coordinates describe a vector relative to a basis; changing basis changes the coordinates, not the underlying vector.

Worked example

Adding (1, 2) and (3, −1) gives (4, 1). Multiplying (1, 2) by 3 gives (3, 6).

The math

In Rn\mathbb{R}^n, vector addition and scalar multiplication act coordinate by coordinate.

In machine learning

Vectors represent features, displacements, signals, and model parameters.

Go deeper

Sources

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