Linear Algebra › Section C · Determinants › Topic C.1
Determinants and cofactor expansion
Every square matrix carries a single number, its determinant, that says at a glance whether the matrix can be inverted. This topic defines that number and shows how to compute it by expanding along any row or column.
In this topic
- One number for a square matrix
- The 2 x 2 determinant
- Minors and cofactors
- Cofactor expansion
- Worked example: a 3 x 3 determinant
- Worked example: let the zeros work
- Triangular matrices
- Sarrus's rule and the cost of expansion
- A short history
- Common mistakes to avoid
- Key takeaways
This topic is part of Wuanberri Pro. Checking your access…