Neural networks and the derivatives of the cost function

[2sin54]

Hello. I need some guidance on the derivation of the derivatives of the quadratic cost function (CF) in an artificial neural network. I can derive the equations for the forward propagation with no trouble but when it comes to finding the derivative of the CF with respect to the weight matrix (matrices) I struggle to distinguish where to use the Hadamar product, where to use the dot matrix product and the order of the multiples. Does anyone know some good resources where I could see a thorough derivation of this OR linear algebra resource relevant to my question?

 

[Edgardo]

Here is a derivation from stats.stackexchange that you may find helpful. It is basically about the chain rule for derivatives.