Answer:
Here's the MatLab code to complete the tasks:
```
% 1. Define an array x(6,6) and fill it with integer random numbers in the interval 0 to 5. Print the array
x = randi([0,5],6,6);
disp(x);
% 2. Define an array y(6,6) and fill it with integer random numbers in the interval of -5 to 15. Print the array
y = randi([-5,15],6,6);
disp(y);
% 3. Define an array z(6,6) and fill it with: z=5x3 −8xy
z = 5*x.^3 - 8*x.*y;
disp(z);
% 4. Use the switch construct to perform the following options:
% a. Find the sum of the element in both diagonal of z. Use "fprintf" to print the result.
sum_diag = sum(diag(z)) + sum(diag(fliplr(z)));
fprintf('The sum of the elements in both diagonals of z is %d.\\', sum_diag);
% b. How many elements in z have the value -1 "fprintf" the result.
num_neg_one = sum(z(:) == -1);
fprintf('There are %d elements in z that have the value -1.\\', num_neg_one);
% c. How many elements of z has a value greater than 12, "fprintf" the result.
num_greater_twelve = sum(z(:) > 12);
fprintf('There are %d elements in z that have a value greater than 12.\\', num_greater_twelve);
% d. What is the sum of numbers in the 2 by 2 inner array. Print the results.
inner_array = z(2:3,2:3);
sum_inner_array = sum(inner_array(:));
fprintf('The sum of the numbers in the 2 by 2 inner array is %d.\\', sum_inner_array);
```
This code defines arrays `x`, `y`, and `z` as instructed, then performs the four tasks using a switch statement. Task a is accomplished by using the `diag` function to extract the two diagonals of `z`, summing them, and printing the result with `fprintf`. Task b is accomplished by using logical indexing to find all elements of `z` that are equal to -1, summing them, and printing the result. Task