Hi @Sarah Molina Esteves ,
You have already defined a function named matrix that takes three arguments: b, L, and U. The function calculates the matrix A by multiplying L and U and then solves for x using the equation x = inv(A) * b. When calling the matrix function, you need to provide the inputs b, L, and U in the correct format. Since b is a vector and L, U are matrices, you should input them as follows:
b = [a; b; c];
L = [d, e, f; g, h, i; j, k, l];
U = [m, n, o; p, q, r; s, t, u];
x = matrix(b, L, U);
In MATLAB, vectors are defined using square brackets [ ] and semicolons ; to separate elements vertically, while matrices are defined using square brackets [ ] and commas , to separate elements horizontally within rows.I think this is what @Adriano Filippo Inno is trying to tell you. Hope this helps.
