How to Find Determinant in MATLAB: Syntax and Examples

In MATLAB, you find the determinant of a matrix using the det() function. Simply pass your square matrix as an argument to det(), and it returns the determinant value.

Syntax

The basic syntax to find the determinant of a matrix A is:

• d = det(A): Returns the determinant d of the square matrix A.
• The matrix A must be square (same number of rows and columns).

matlab

d = det(A)

Example

This example shows how to calculate the determinant of a 3x3 matrix in MATLAB.

matlab

A = [1 2 3; 4 5 6; 7 8 9];
d = det(A);
d

Output

d = 0

Common Pitfalls

Common mistakes when finding determinants in MATLAB include:

• Using a non-square matrix, which causes an error.
• Confusing the determinant with other matrix operations like trace or inverse.
• Not storing the result or printing it, so you don't see the output.

matlab

B = [1 2 3; 4 5 6];
d = det(B); % This will cause an error because B is not square

% Correct way:
C = [1 2; 3 4];
d = det(C);

Output

Error using det
Input must be a square matrix.

d = -2

Quick Reference

Remember these key points when using det() in MATLAB:

• Input must be a square matrix.
• Output is a scalar number representing the determinant.
• Use det() for numerical matrices only.

Key Takeaways

Use det(A) to find the determinant of a square matrix A in MATLAB.

The input matrix must be square; otherwise, MATLAB will return an error.

The determinant is a single number that can be zero, positive, or negative.

Common errors come from using non-square matrices or confusing determinant with other matrix functions.