I was going through the second answer of this question but I can't understand if it is correct to expand the determinant along the column 1st and then in the recursive step to compute the determinant along the row?
Proving the determinant of a tridiagonal matrix with $-1, 2, -1$ on diagonal.
How do I compute the determinant of a tridiagonal matrix. I was going through the 1st answer to this question and there I saw that $\det(\Delta_n))=a_n\Delta_{n-1}-bc\Delta_{n-2}$ .I am unable to understand how are we getting $-bc\Delta_{n-2}$ - is the expansion along the row or the column? I need some help or an explicit answer as I have been stuck with these types of matrices for a long time.
