Thread: determinant of this 4x4 matrix

hey guys i keep getting lost in this determinant:

[1 -2 3 -12]
[-5 12 -14 19]
[-9 22 -20 31]
[-4 9 -14 15]


I know you have to do the row expansion but for some reason im getting lost.

Originally Posted by tn11631

hey guys i keep getting lost in this determinant:

[1 -2 3 -12]
[-5 12 -14 19]
[-9 22 -20 31]
[-4 9 -14 15]


I know you have to do the row expansion but for some reason im getting lost.

If you understand the process then the error will be in your arithmetic (I doubt you will find too many people willing to check the arithmetic). You should leave it for a day or so and then go back and check it with fresh eyes.