## The Backpropagation Algorithm

Preliminaries An Introduction to Backpropagation and Multilayer Perceptrons Culculus 1,2 Linear algebra Jacobian matrix Architecture and Notations1 We have seen a three-layer network is flexible in approximating functions(An Introduction to Backpropagation and Multilayer Perceptrons). If we had a more-than-three-layer network, it could be used to approximate any functions as accurately as we want. However, another trouble that came to us is the learning rules. This problem almost killed neural networks in the 1970s....