Studied Linear Algebra
Sunday's are for Algebra. 

Watched a lecture about Positive Definite Matrices from MIT Courseware 

Few notes: 
  • Matrix has to be symmetric
  • All its eigenvalues are positive
How to find out if a Matrix is positive definite? 

1. By finding its eigenvalues and checking all > 0 
2. By checking the pivots of the matrix are > 0, reducing to echelon form 
3. By calculating determinants from the upper left.