# Calculating Minors of a 3x3 matrix not giving correct output [closed]

The function Minors[] does not return what its suposse to. Example:

mat = {{a, b, c}, {l, m, n}, {x, y, z}}
mat // MatrixForm
Minors[mat] // MatrixForm


The output for minors is :

{{-b l + a m, -c l + a n, -c m + b n}, {-b x + a y, -c x + a z, -c y +
b z}, {-m x + l y, -n x + l z, -n y + m z}}


It calculates all the minors but places them in wrong possitions. Minor for possition 1,1 is in position 3,3. On symbolab it calculates it correctly. Am i not using the correct function? What am i missing here? • Indeed, Minors does not what one usually expects. Please read the documentation of Minors more carefully, in particular the "Details" section. Apr 29 '20 at 10:52
• The output is consistent with the documentation of Minors, see first point of Details. I agree it's not the definition I know either though. Apr 29 '20 at 10:53
• You could always 'roll your own': Table[Det@Drop[mat, {i},{j}], {i,3},{j,3}]//MatrixForm. Also, this post by Carl Woll might be of interest. Apr 29 '20 at 13:56
• From the documentation, Map[Reverse, Minors[mat], {0,1}] may be what you are looking for? And: Map[Reverse, Minors[mat], {0,1}]==Table[Det@Drop[mat, {i},{j}], {i,3},{j,3}] Apr 29 '20 at 22:09

(mat = {{a, b, c}, {l, m, n}, {x, y, z}}) // MatrixForm min = Minors[mat]; 