why the conv_backward test instead of sending dZ as argument is sending just Z?

“Z” is just a variable name. It could be “George” if they wanted to.

Probably it should be fixed to remove confusion though.

understood, thank you

Ultimately, it’s because “Z” is the variable name returned by conf_forward().

Yes that is clear, but the conv_backward function is expecting dZ no Z

The variable named “Z” becomes named “dZ” as soon as the conv_backward function() is called. Values are defined by their order in the list of function parameters, not the name used in the calling function.

This is a fundamental rule of all programming lanuages.

understood, but it was generated as Z in a previous function not as dZ. I understand that as soon the next function is called it does not matter where it came from, but it is misleading