The Matrix Variable Problem

What does this question mean? What is the command code in this matrix?

[Mario Malic]

Can you take a look at function ones or zeros in documentation and see how can you create such matrix.

[Ting Chie Yu]

I'm not very sure the quetion mean because the diagram is 3x3 matrix but what's mean by 3x4 matrix full of 5's.

[Jan]

No, the diagram is not a 3x3 matrix. The dots mean, that there is a not specified number of elements not show. The text explains, that this is a 3x4 matrix: 3 rows, 4 columns. "Full of 5's" means, that all elements are 5's.

[Ting Chie Yu]

All Right Thank You!

Answer 1

[Jan]

You must use ones or zeros sounds, like you should use one of these commands. Then read their help text:

help ones
help zeros

% Or more exhaustively
doc ones
doc zeros

Now you have learned, how to determine the size of the output of these commands. You will need:

bMat = ones(3, 4)
% or
bMat = zeros(3, 4)

In the first case the elements are ones, in the second case zeros. So how can you change them to 5? There are a lot of ways:

% Here it does not matter if ONES or ZEROS has been used:
bMat(:) = 5
bMat(:, :) = 5

% or
bMat = ones(3, 4) * 5

% or
bMat = ones(3, 4) + 4

% or
bMat = zeros(3, 4) + 5

% or
bMat = ones(3, 4);
bMat = bMat + bMat + bMat + bMat + bMat;

% or
bMat = [ones, ones, ones, ones; ...
        ones, ones, ones, ones; ...
        ones, ones, ones, ones]

% or
bMat = [ones(2, 3), ones(2, 1); ones(1, 4)] + 4;

% or:
bMat = ones(1, 4) * 5 .* ones(3, 1)

The forum is not efficient to learn the fundamental basics. I recommend to learn Matlab's Onramp at first.

I know I've solved your homework here. But if you carefully read all suggestions, you will learn something also.