Characteristic Polynomial Calculator

Looking for a tool to find eigenvalues for any square matrix for you? No problem, as you can try our free characteristic polynomial calculator now!

Table of Contents:

Introduction to a Characteristic Polynomial Calculator:

Characteristic polynomial calculator is an online tool that is designed to determine the characteristic polynomial of a given square matrix. Our calculator simplifies the process of finding eigenvalues from the characteristic polynomial equation.

Characteristic Polynomial Calculator with steps

It's a valuable tool for students, researchers, and professionals, who are working with matrices and linear algebra to get solutions without manual calculation.

What is a Characteristic Polynomial?

Characteristic Polynomial of a square matrix A is defined as the determinant equation where an indeterminate (variable) λ commutes with the identity matrix of the same order as A has to find the eigenvalues. It is denoted as p(λ).

The characteristic polynomial roots are the eigenvalues of the square matrix A. The equation can be written as follows:

$$ p(λ) \;=\; det(A−λI) $$

Calculation Process in Characteristic Equation Calculator:

Characteristic polynomial of a matrix calculator provides a straightforward method to calculate the characteristic polynomial of any square matrix, for eigenvalues. Follow these simple steps such as:

Step 1: Identify the given square matrix A in the dimensions n×n order. The elements of a given matrix can be real numbers or complex numbers depending on the type of matrix.

Step 2: To make the given matrix in the form of a characteristic polynomial equation such as IA−λII, subtract matrix A with an indeterminate λ and I matrix.

Step 3: Calculate the determinant of the characteristic polynomial equation to find the eigenvalue such as:

$$ p(λ) \;=\; det\; (A−λI) $$

Step 4: The characteristic equation solver gives the characteristic polynomial p(λ) in a simplified expression. This polynomial provides valuable information about the eigenvalues of the original matrix A.

Solved Example of the Characteristic Polynomial

Let's see an example of a characteristic polynomial equation with a solution to get better clarity about the working process of the characteristic equation of matrix calculator.

Example: Find Matrix Characteristics Polynomial,

$$ \left[ \begin{matrix} 5 & -6 & 2 \\ -3 & 1 & -4 \\ 2 & -4 & 3 \\ \end{matrix} \right] $$

Solution:

$$ A - \lambda I $$

$$ =\; \left| \begin{matrix} (5 - \lambda ) & -6 & 2 \\ -3 & (1 - \lambda ) & -4 \\ 2 & -4 & (3 - \lambda ) \\ \end{matrix} \right| $$

$$ =\; (5 - \lambda)((1 - \lambda) \times (3 - \lambda) - (-4) \times (-4)) - (-6)((-3) \times (3 - \lambda) - (-4) \times 2) + 2((-3) \times (-4) - (1 - \lambda) \times 2 $$

$$ =\; (5 - \lambda) \biggr( \biggr(3 - 4\lambda + \lambda^2 \biggr) - 16 \biggr) + 6 ((-9 + 3 \lambda) - (-8)) + 2( 12 - (2 - 2 \lambda)) $$

$$ =\; (5 - \lambda) \biggr( -13 - 4\lambda + \lambda^2 \biggr) + 6(-1 + 3 \lambda) + 2(10 + 2 \lambda) $$

$$ =\; \biggr( -65 - 7\lambda + 9 \lambda^2 - \lambda^3 \biggr) + (-6 + 18 \lambda) + (20 + 4 \lambda) $$

$$ =\; \biggr(- \lambda^3 + 9 \lambda^2 + 15 \lambda - 51 \biggr) $$

$$ =\; - \biggr(\lambda^3 - 9 \lambda^2 - 15 \lambda + 51 \biggr) $$

How to Use the Characteristic Polynomial Calculator?

Characteristic equation calculator has a simple design that makes it easy for you to know how to use it for the evaluation of characteristic polynomial equations, only when you follow our instructions that are given as:

  • Choose the size of the matrix from the given field for the characteristic equation.
  • Enter the element of a square matrix to find the characteristic equation in the input field.
  • Review the given matrix before hitting the calculate button to start the evaluation process in the characteristic equation calculator.
  • Click the “Calculate” button to get the result of your given characteristic polynomial problem.
  • If you are trying our characteristic polynomial of a matrix calculator for the first time then you can use the load example to learn more about this method.
  • Click on the “Recalculate” button to get a new page for finding more example solutions of characteristic polynomial problems to get eigenvalue.

Final Result of Characteristic Equation Solver:

Characteristic equation of matrix calculator gives you the solution from a given characteristic polynomial when you add the input into it. It included as:

  • Result Option

When you click on the result option the characteristic polynomial calculator gives you a solution to the square matrix problem to find characteristic polynomials.

  • Possible Steps

When you click on it, this option will provide you with a solution where all the calculations of characteristic polynomial process steps are mentioned.

Benefits of Using the Characteristic Equation Calculator:

The characteristic polynomial of a matrix calculator provides you with many benefits that help you to calculate square matrix problems and give you solutions without any trouble. These benefits are:

  • A characteristic equation solver is a free-of-cost tool so you can use it for free to find characteristic polynomial problem solutions without paying anything.
  • It is an adaptable tool that can manage various types of matrices to calculate the characteristic polynomial equation.
  • Our characteristic equation of matrix calculator helps you to get conceptual clarity for the characteristic polynomial process when you use it for practice by solving more examples.
  • It saves the time that you consume on the calculation of the characteristic polynomial problems.
  • Characteristic polynomial calculator is a reliable tool that provides you with accurate solutions whenever you use it to calculate the characteristic polynomial without any man-made error in evaluation.
  • A characteristic equation calculator provides the solution without imposing any restriction which means you can use it multiple times.
Related References
Frequently Ask Questions

What is the difference between characteristic polynomial and minimal polynomial?

The characteristic polynomial and the minimal polynomial are both concepts from linear algebra for square matrices or linear transformations on vector spaces. Both polynomials are important in linear algebra, they serve different purposes:

Characteristic Polynomial:

For a square matrix A, the characteristic polynomial pA(x) is defined as pA(x) = det⁡ (xI−A), where I is the identity matrix of the same size as A. It helps in finding eigenvalues of the matrix A. The roots of pA(x) are given the eigenvalues of A.

Minimal Polynomial:

The minimal polynomial mA(x) of a square matrix A is the process in which the leading term coefficient 1 of least degree such that mA(A) = 0, where mA(A) denotes the matrix polynomial obtained by substituting A into mA(x). It builds the relationship between A and its eigenvalues minimally, especially when mA(x)is the smallest polynomial such that mA(A) = 0, which means A satisfies its minimal polynomial.

Therefore, the characteristic polynomial focuses on eigenvalues, whereas the minimal polynomial provides insights into the structural properties of the matrix A itself.

What is the characteristic polynomial of the zero matrix?

For the zero matrix A = 0, where all entries are zero, the characteristic polynomial can be determined as follows: Let A be the order of n × n zero matrix:

$$ A \;=\; \left(\begin{matrix} 0 & 0 & \cdots & 0 \\ 0 & 0 & \cdots & 0 \\ \vdots & \vdots & \ddots & \vdots \\ 0 & 0 & \cdots & 0 \\ \end{matrix}\right) $$

Characteristic Polynomial Calculation:

  1. Make a matrix in the form of this equation IA−λI:

$$ A - λI \;=\; \left(\begin{matrix}0 - λ & 0 & \cdots & 0 \\ 0 & 0 - λ & \cdots & 0 \\ \vdots & \vdots & \ddots & \vdots \\ 0 & 0 & \cdots & 0 - λ \\ \end{matrix} \right) \;=\; \left(\begin{matrix} -λ & 0 & \cdots & 0 \\ 0 & -λ & \cdots & 0 \\ \vdots & \vdots & \ddots & \cdots \\ 0 & 0 & \cdots & -λ \\ \end{matrix} \right) $$

  1. Find the Determinant of the above matrix,

$$ det(A - λI) \;=\; det \left(\begin{matrix} -λ & 0 & \cdots & 0 \\ 0 & -λ & \cdots & 0 \\ \vdots & \vdots & \ddots & \vdots \\ 0 & 0 & \cdots & λ \\ \end{matrix} \right) $$

How to find the characteristic polynomial of a 2x2 matrix?

To find the characteristic polynomial equation of a matrix A in 2 by 2 order such as:

$$ A \;=\; \left(\begin{matrix} 3 & 1 \\ 1 & 2 \\ \end{matrix} \right) $$

Solution:

The characteristic of the polynomial equation is det(λ - AI):

Form A - λI:

$$ A - λI \;=\; \left(\begin{matrix} 3 - λ & 1 \\ 1 & 2 - λ \\ \end{matrix} \right) $$

Compute det (A - λI):

$$ det(A - λI) \;=\; (3 - λ)(2 - λ) - (1)(1) $$

$$ =\; 6 - 5λ + λ^2 $$

How to find determinant from characteristic polynomial?

To find the determinant of a square matrix from its characteristic polynomial, use the following method which is:

Consider a 2 × 2 matrix A:

$$ A \;=\; \left(\begin{matrix}a & b \\ c & d \\ \end{matrix} \right) $$

The characteristics polynomial p(λ) is,

$$ p(λ) \;=\; λ^2 - trace(A) . λ + det(A) $$

Where:

$$ trace (A) \;=\; a + d $$

$$ det (A) \;=\; ad - bc $$

Thus, the determinant det⁡(A) can be directly obtained from the characteristic polynomial when you keep the constant term equal to zero c = 0 then det(A) = c.

What are eigenvalue characteristic polynomial equations of a matrix?

The characteristic polynomial equation of a matrix is associated with the matrix with the help of finding its eigenvalues.

In a square matrix A which has n×n order, the characteristic polynomial p(λ) is defined as p(λ) = det⁡(A−λI), where λ is an indeterminate (variable).

The characteristic polynomial root given when you keep p(λ) = 0 gives the eigenvalues λ1, λ2,…, λn of the matrix A. It gives insights into the matrix A's eigenvalues. The characteristic polynomial plays a crucial role in eigenvalue analysis as it gives a comprehensive way to determine the eigenvalues of a matrix, which are essential in various fields of mathematics, physics, and engineering.

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