I dont know what I am doing wrong. I have attached the error snippet
The error means that there is something wrong with the multiplication, check the shapes of a_slice_prev and W, they are not as suposed to be to achieve the multiplication operation (keep in mind these are vectors).
Thank you for the answer. Seems like I had parentheses mistake for n_H and n_W formula
what you mean by it?
I mean their shapes are not right to multiply them.