00:01
In this problem, our goal is to find the determinant of a 3x3 matrix that's given.
00:06
I've also drawn the corresponding checkerboard pattern or its sign matrix for a 3x3 matrix below.
00:13
I'm going to choose to expand this determinant by its first column of negative 2, 0, negative 1.
00:21
Because i see a 0 in there, which will simplify our work later.
00:26
So expanding this, we'll bring the first term negative 2 times its minor, or the matrix formed when i cross out the first row and first column.
00:36
So that leaves over 3, 4, 2, 6, then minus 0 times it's minor, but i don't really care what its minor is, because whatever it is, it'll be multiplied by 0.
00:50
So it's irrelevant, and then minus 1 times this minor of 5 -1, 3, 4...