the 3-by-3 matrix a whose elements are a(1,1) =-2.4, a(1,2) =7.5, a(1,3) =2.5, a(2,1) =7.1, a(2,2) =-1.3, a(2,3) =6.2, a(3,1) =-2.4, a(3,2) =7.5, a(3,3) =2.5 in matlab

You can create a 3-by-3 matrix in MATLAB by defining each element within square brackets ([]), separated by commas or spaces. Then you can assign the resulting matrix to a variable using the equal sign (=). Here is an example code that creates a 3-by-3 matrix named "a":

main.m
a = [-2.4, 7.5, 2.5; 7.1, -1.3, 6.2; -2.4, 7.5, 2.5];
54 chars
2 lines

In the above code, semicolons separate the rows of the matrix, and commas (or spaces) separate the elements within each row. The result is a variable named "a" that contains the 3-by-3 matrix you specified.