Backpropagation chain rule example
Why do we seem to disregard the weights of the second layer (in blue)?
-----because activation function is after that block, so differential with the o/p y is as good as with the weight.
The red circle, should this not be ∂y2 (followed by ∂y2∂P3)?
-----y2 and y1 is the o/p of the same block i.e. both must be same