* element-wise operation in dZ[l]

Course Q&A Deep Learning Specialization Neural Networks and Deep Learning
1

Hello,

I have been trying to calculate dz[1] manually and I got this expression: dz[2] x dw[2] x g[1]'(z[1]). However, I do not really understand where the element-wise operation (*) comes from. If anyone could help me, I would appreciate it.

Thanks in advance.

1 Like
2

Hello Julio,

is this related to any assignment in particular?

Can you please mention the week and assignment name you are working on?

Regards
DP

3

Hello,

This issue appears in week 3, in the explanation of backward propagation.

4

Do you have an understanding about what element-wise operation is?

5

Yes, I understand that the element-wise product consists in multipliying each element without adding later. But I do not really understand why the operation is element-wise and not a dot product.