Lecture 18. Determinant.
- Det(A), |A|, determinant has signs +,-.
- Invertibility. Det(A) > 0 , invertible.
- Sometimes, determinant feels like the area.
- First Property: Det(I) = 1
- Second Property: Row exchanging reverse the sign of the determinant.
- A permutation matrix is a row exchanging of I. So the determinant of Permutation matrices is +-1.
- How to compute in 2D