218 - Intro to Matrices and Vectors

Real Numbers (R)

All real numbers, also known as scalars.

Membership Symbol (∈)

Indicates membership.

Vector in R^n

A list of n scalars organized vertically into a list (lower-case bold letters).

Matrix

An m x n matrix is an array of scalars with m rows and n columns.

Square Matrix

An n x n matrix is a square.

(i,j) Entry of a Matrix

The scalar in the ith row and jth column of a matrix.

Transposition Property

(A^T)T = A.

Symmetric Matrix

S^T = S.

Trace of a Matrix

The sum of its diagonal elements.