I’ve got every test above correct, but the cell tells me that the value of W1 is incorrect and the output of W1 remains the same after the gradient descent.
I can not find where the problem is. Please help!

Can you share your lab ID with me ? In the assignment, when you click the top right “Help” button, a panel will open and your lab ID will be shown at the bottom.

Hi, mentor! I want to report a mistake in the instructions of Week 3, Exercise 9.
The first derivative of AL (dAL) should be ‘dAL = - (np.divide(Y, AL) + np.divide(1 - Y, 1 - AL))’, but the instructions said that ‘dAL = - (np.divide(Y, AL) - np.divide(1 - Y, 1 - AL))’.

In the thread you gave, the formula should be the picture I’ve captured above, which is the formula I’ve gave in the previous reply.
But in the instructions, it uses the “-” sign, which is a mistake.

No, it is correct. Check the parentheses carefully. The leading minus sign multiplies the entire expression. If you expand it out without the parens, you’ll see that you get the same result as shown in the image from the thread.