# 3.2 matrix operations.pptx - Operations on Matrices u2022...

• 20

This preview shows page 1 - 6 out of 20 pages.

Operations on Matrices Definition and Use Basic operations Multiplication Inverses
Definition of Matrix A matrix is an array of objects, usually numbers. You used some in your work in Unit 2. All of these are examples of matrices. The first two are “square”, the first 2x2 and the second 3x3. The third one is 3x2, the fourth one a “row” matrix at 1x3, and the fifth one a “column” matrix at 3x1.
Use of Matrices Sometimes, matrices are just lists of numbers and a matrix is the best way to organize them. More frequently, the numbers stand for something. You used matrices where the numbers stood for coordinate points; they can also stand for coefficients of equations, among other things.
Use of Matrices For example, the system of equations 4x 1 – 5x 2 = 13 2x 1 + x 2 = 7 can be inserted into a matrix that looks like this: In matrix (array) form, the system of equations is much easier for a computer to work with.
Basic Operations on Matrices Matrices that are the same size can be added or subtracted: = A matrix can also be multiplied easily by a constant: