Night out cycle - phd comics

I used to do this sometime back (I mean the last 2 years). Thankfully, I stopped this 4 months back.

Positive definite matrices and quadratic minimization

I was looking to understand more on positive definite matrices and a couple of theorems. I found a nice summary of positive definite matrices, their properties and role in quadratic minimization on the web here. Another link here. Another here.
Also an ultra-quick summary of Linal.