# Linear-Algebra-MIT-Gilbert-Strang-(L27-L29)

# Lecture 27 Positive Definite and its Graphical analysis

- How to check whether it is positive definite.

Determinant > 0

Eigenvalue > 0

pivot: pivot and pivot divided by a (for the second pviot, multiply together to become determinant)

**x^T A x > 0**

Semi definite when it is equal to 0