- #1
John777
- 27
- 1
Prove determinate of matrix is 150
1 2 3 4
4 3 2 1
0 -1 2 3
1 6 4 -2
My solution is incorrect and maybe my method is incorrect but I can't figure it out. I went down the first column to make use of that zero.
Here is the basic method (aij)(-1)ij*Det(3x3) >> (aij)(-1)ij * (aij)(-1)ij*Det(2x2) where the second aij and (-1)ij are for the newly created 3x3 matrix
First term:
(1)(-1)2(3)(-1)2[(2)(-2)-(4)(3)] = -48
Second term:
(4)(-1)3(2)(-1)2[(2)(-2)-(4)(3)] = 128
Third term = 0
Fourth term
(1)(-1)5(2)(-1)2[(2)(3)-(2)(1)] = -8
Det = -48 +128 - 8 = 72.