The Product of the Two Matrices

Oct 13, 2025 by wbrum.org 101 views

Introduction

In mathematics, matrix multiplication is a fundamental operation that involves multiplying two matrices to obtain a new matrix. The resulting matrix is obtained by multiplying the elements of each row of the first matrix with the elements of each column of the second matrix. In this article, we will explore how to find the product of two matrices using the given example.

What is Matrix Multiplication?

Matrix multiplication is a binary operation that takes two matrices as input and produces another matrix as output. The resulting matrix is obtained by multiplying the elements of each row of the first matrix with the elements of each column of the second matrix. The number of columns in the first matrix must be equal to the number of rows in the second matrix.

Example: Finding the Product of Two Matrices

Let's consider the following example:

$\begin{array}{c} \left[\begin{array}{rrr} 4 & -2 & 10 \\ 2 & 4 & -3 \end{array}\right] \left[\begin{array}{r} 1 \\ -2 \\ 5 \end{array}\right] \end{array}$

To find the product of these two matrices, we need to multiply the elements of each row of the first matrix with the elements of each column of the second matrix.

Step 1: Multiply the Elements of Each Row of the First Matrix with the Elements of Each Column of the Second Matrix

Let's start by multiplying the elements of the first row of the first matrix with the elements of the first column of the second matrix.

$\begin{array}{r} (4)(1) + (-2)(-2) + (10)(5) \\ = 4 + 4 + 50 \\ = 58 \end{array}$

Now, let's multiply the elements of the first row of the first matrix with the elements of the second column of the second matrix.

$\begin{array}{r} (4)(-2) + (-2)(-2) + (10)(5) \\ = -8 + 4 + 50 \\ = 46 \end{array}$

Finally, let's multiply the elements of the first row of the first matrix with the elements of the third column of the second matrix.

$\begin{array}{r} (4)(5) + (-2)(-2) + (10)(5) \\ = 20 + 4 + 50 \\ = 74 \end{array}$

Step 2: Multiply the Elements of Each Row of the First Matrix with the Elements of Each Column of the Second Matrix (Continued)

Now, let's multiply the elements of the second row of the first matrix with the elements of the first column of the second matrix.

$\begin{array}{r} (2)(1) + (4)(-2) + (-3)(5) \\ = 2 - 8 - 15 \\ = -21 \end{array}$

Next, let's multiply the elements of the second row of the first matrix with the elements of the second column of the second matrix.

$\begin{array}{r} (2)(-2) + (4)(-2) + (-3)(5) \\ = -4 - 8 - 15 \\ = -27 \end{array}$

Finally, let's multiply the elements of the second row of the first matrix with the elements of the third column of the second matrix.

$\begin{array}{r} (2)(5) + (4)(-2) + (-3)(5) \\ = 10 - 8 - 15 \\ = -13 \end{array}$

The Product of the Two Matrices

Now that we have multiplied the elements of each row of the first matrix with the elements of each column of the second matrix, we can write the product of the two matrices as follows:

$\begin{array}{c} \left[\begin{array}{rr} 58 & 46 & 74 \\ -21 & -27 & -13 \end{array}\right] \end{array}$

Conclusion

In this article, we have explored how to find the product of two matrices using the given example. We have seen that matrix multiplication involves multiplying the elements of each row of the first matrix with the elements of each column of the second matrix. The resulting matrix is obtained by adding the products of the corresponding elements of the two matrices. We have also seen that the number of columns in the first matrix must be equal to the number of rows in the second matrix.

Applications of Matrix Multiplication

Matrix multiplication has many applications in mathematics and computer science. Some of the applications of matrix multiplication include:

Linear Algebra: Matrix multiplication is used to solve systems of linear equations and to find the inverse of a matrix.
Computer Graphics: Matrix multiplication is used to perform transformations on 2D and 3D objects.
Machine Learning: Matrix multiplication is used to train neural networks and to perform other machine learning tasks.
Data Analysis: Matrix multiplication is used to perform data analysis and to find patterns in data.

Common Mistakes to Avoid

When performing matrix multiplication, there are several common mistakes to avoid. Some of these mistakes include:

Not checking the dimensions of the matrices: Before performing matrix multiplication, it is essential to check that the number of columns in the first matrix is equal to the number of rows in the second matrix.
Not multiplying the elements correctly: When multiplying the elements of each row of the first matrix with the elements of each column of the second matrix, it is essential to multiply the corresponding elements and add the products.
Not checking the result: After performing matrix multiplication, it is essential to check the result to ensure that it is correct.

Conclusion

Introduction

Matrix multiplication is a fundamental operation in mathematics and computer science. It involves multiplying the elements of each row of the first matrix with the elements of each column of the second matrix. In this article, we will answer some of the most frequently asked questions about matrix multiplication.

Q: What is Matrix Multiplication?

A: Matrix multiplication is a binary operation that takes two matrices as input and produces another matrix as output. The resulting matrix is obtained by multiplying the elements of each row of the first matrix with the elements of each column of the second matrix.

Q: What are the Dimensions of a Matrix?

A: The dimensions of a matrix are the number of rows and columns it has. For example, a 2x3 matrix has 2 rows and 3 columns.

Q: What is the Order of Matrix Multiplication?

A: The order of matrix multiplication is essential to ensure that the resulting matrix is correct. The order of matrix multiplication is as follows:

First, multiply the elements of each row of the first matrix with the elements of each column of the second matrix.
Then, add the products of the corresponding elements of the two matrices.

Q: What is the Result of Matrix Multiplication?

A: The result of matrix multiplication is a new matrix that is obtained by multiplying the elements of each row of the first matrix with the elements of each column of the second matrix.

Q: What are the Applications of Matrix Multiplication?

A: Matrix multiplication has many applications in mathematics and computer science. Some of the applications of matrix multiplication include:

Linear Algebra: Matrix multiplication is used to solve systems of linear equations and to find the inverse of a matrix.
Computer Graphics: Matrix multiplication is used to perform transformations on 2D and 3D objects.
Machine Learning: Matrix multiplication is used to train neural networks and to perform other machine learning tasks.
Data Analysis: Matrix multiplication is used to perform data analysis and to find patterns in data.

Q: What are the Common Mistakes to Avoid in Matrix Multiplication?

A: When performing matrix multiplication, there are several common mistakes to avoid. Some of these mistakes include:

Not checking the dimensions of the matrices: Before performing matrix multiplication, it is essential to check that the number of columns in the first matrix is equal to the number of rows in the second matrix.
Not multiplying the elements correctly: When multiplying the elements of each row of the first matrix with the elements of each column of the second matrix, it is essential to multiply the corresponding elements and add the products.
Not checking the result: After performing matrix multiplication, it is essential to check the result to ensure that it is correct.

Q: How Do I Perform Matrix Multiplication?

A: To perform matrix multiplication, follow these steps:

Check the dimensions of the matrices to ensure that the number of columns in the first matrix is equal to the number of rows in the second matrix.
Multiply the elements of each row of the first matrix with the elements of each column of the second matrix.
Add the products of the corresponding elements of the two matrices.
Check the result to ensure that it is correct.

Q: What is the Formula for Matrix Multiplication?

A: The formula for matrix multiplication is as follows:

C = AB

where C is the resulting matrix, A is the first matrix, and B is the second matrix.

Conclusion

In conclusion, matrix multiplication is a fundamental operation in mathematics and computer science. It involves multiplying the elements of each row of the first matrix with the elements of each column of the second matrix. By following the steps outlined in this article, you can perform matrix multiplication correctly and avoid common mistakes.