# 7. Neural Networks Part II

   
We just saw what neural networks are made of, what are the math done in a node and how to compute all values of activation units, leading to intermediary predictions.

Let's now cover the backpropagation algorithm, which is the core of how neural networks are trained.  

* __What are the cost functions for neural network?__
* __How should the weights be initialized?__
* __How does backpropagation work?__