# Math Help - Simplifying mathematical notations

1. ## Simplifying mathematical notations

Hi, I need some help simplifying the above chunk into a (single?) formula. I know nuts about notations, so any help is appreciated

I don't know if you can tell what I'm trying to do; it's uhm. some instructions on how to get determinant of matrix = 1.

Thanks!

2. Originally Posted by vongst

Hi, I need some help simplifying the above chunk into a (single?) formula. I know nuts about notations, so any help is appreciated

I don't know if you can tell what I'm trying to do; it's uhm. some instructions on how to get determinant of matrix = 1.

Thanks!
That is almost incomprehensible, provide more context.

Your matrix $X$ has ones down the diagonal, and zeros above the diagonal. Expanding the determinant along the first row gives:

$|X|=|X'|$

where $X'$ is the matrix obtained from $X$ by deleting the first row and column

CB