How would I find the the determinants of the following matrices without using my calculator? Is there a fast way?
Thanks in advance!
Hello,
The determinant of a matrix nxn is 0 iff the rank of the matrix is < n.
If two columns or rows of a matrix nxn are linearly dependent, then the matrix is not of rank n.
For the first one, the 4th column is 11 times the 1st one.
For the second one, it is obvious that with the null column, the matrix is not of rank n.
Edit : excuse me, I confused myself between rank and dimension