Iām not really sure TBH. I was concerned about what I can/canāt post here so I wasnāt more explicit the first time but let me paste a screenshot here

Posting images of the error messages is always allowed.

The test with lambda_ = 1.5 shows that your cofi_cost_func() doesnāt handle the regularization calculation correctly.

The notebook gives you all of the data for this test case, so you can calculate the regularized part by hand and then look at your code and instrument it with print() statements to sort out the issue.

Also, if you look at all of the Hint code sections in the notebook, they give you the entire solution. There are a lot of places for bad indentation and misplaced parenthesis.

Donāt worry about the later assert from unit test in test_cofi_cost_func() until you fix the built-in test.

When I change from the unregularized J += to the regularized J +=, should I still get 13.67 for lambda_ = 0? I donāt get 13.67 when I run the regularized line of code.

The equation for J += under the regularization details hint is accurate such that if I replace the unregularized line in the script with the equation for regularized J +=, I should get 13.6 for lambda_ = 0 and 28.09 for lambda_ = 1.5?

This statement confuses me.
You should not change your code specifically for either one.
Your code should be able to compute either, with the result due to the value of lambda.

I appreciate your patience, I normally donāt get tripped up like this however for some reason, Iām just not locking in on the approach. Based on your prior message, I understand how to compute either based on lambda. If I just focus on the regularization calculation where lambda = 1.5 for a moment, I should just be able to calculate the squares and sums of W and X, add those together, and multiply by lambda_/2, correct? The screenshot shows the matrices after each operation but Iām clearly not calculating something correctly.

You are right, I certainly had the wrong concept. Adding the two parts together was what I was missing - somehow, I didnāt pick up on that during the recorded lecture. I do think the hints could be more clear but I did figure it based on your last reply - thanks for the assistance.