Matrix determinant (det) in MATLAB - Mini Project: Build & Apply

Matrix determinant (det)

📖 Scenario: You are working with square matrices in MATLAB. You want to find the determinant of a matrix, which is a special number that tells you important things about the matrix, like if it can be inverted.

🎯 Goal: Build a MATLAB script that creates a matrix, sets a size threshold, calculates the determinant only if the matrix size is within the threshold, and then displays the determinant.

📋 What You'll Learn

Create a 3x3 matrix called A with exact values: [1 2 3; 4 5 6; 7 8 9]

Create a variable called max_size and set it to 3

Calculate the determinant of A only if the number of rows in A is less than or equal to max_size, store it in det_A

Display the value of det_A using disp

💡 Why This Matters

🌍 Real World

Calculating determinants helps in solving systems of equations, checking matrix invertibility, and understanding matrix properties in engineering and science.

💼 Career

Matrix operations like determinant calculation are fundamental in data analysis, computer graphics, machine learning, and scientific computing jobs.

1

Create the matrix A

Create a 3x3 matrix called A with these exact values: [1 2 3; 4 5 6; 7 8 9]

MATLAB

% Create matrix A with the given values
% Your code here

Need a hint?

Use square brackets and semicolons to create rows in MATLAB.

2

Set the size threshold max_size

Create a variable called max_size and set it to 3

MATLAB

A = [1 2 3; 4 5 6; 7 8 9];
% Set max_size to 3
% Your code here

Need a hint?

Just assign the number 3 to the variable max_size.

3

Calculate the determinant if size condition is met

Calculate the determinant of A only if the number of rows in A is less than or equal to max_size. Store the result in det_A. Use size(A,1) to get the number of rows and det(A) to calculate the determinant.

MATLAB

A = [1 2 3; 4 5 6; 7 8 9];
max_size = 3;
% Calculate determinant if size condition is met
% Your code here

Need a hint?

Use an if statement to check the size, then calculate determinant with det(A).

4

Display the determinant det_A

Use disp(det_A) to display the value of the determinant stored in det_A.

MATLAB

A = [1 2 3; 4 5 6; 7 8 9];
max_size = 3;
if size(A,1) <= max_size
    det_A = det(A);
else
    det_A = NaN; % Not calculated if size too big
end
% Display the determinant
% Your code here

Need a hint?

Use disp(det_A) to show the determinant on the screen.