Machine Learning Specialization Learnings 1

I’m doing the new Machine Learning Specializationg by Andrew Ng in Coursera, great content so far.

Due to that, I’m refreshing my college Calculus and Linear Algebra.

In the first week we look at Regression Models with Gradent Descent. Wich makes ML an optimization problem of a multi-variable (features) fuction (model). The optmization takes a cost function (J) which represents the error of the fuction to predict the right value given an x.