Error in the parameters of the model

I am struggling to find what went wrong here. All previous test are passed.

{moderator edit - solution code removed}

You did not pass the values of number of iterations, learning rate and print flag on the call to optimize, so you get the default values for those parameters which are declared in the definition of optimize.

The “meta” principle is that ignoring the parameters that are passed in is never a good idea.

Thank you very much.