C3W2 quiz question correct answer has a typo

One of the quiz questions asks for the formula for a 5 dimensional output cost fcn for a multi-task learning problem. The “correct” answer, which I chose, is missing one set of parentheses around a superscript indicating training example number “i.” Superscripts lacking parentheses, brackets, or curly braces are not defined in the course, making this “correct” answer somewhat wrong. Pls fix. Thx!

Hello am003e,

Kindly specify your query. Which particular question are you asking about?


Hi Rashmi, Thanks for the reply. I just dug it up now. The question text is as follows. Please forgive the inelegant text pasting.

Question 2
Your goal is to detect road signs (stop sign, pedestrian crossing sign, construction ahead sign) and traffic signals (red and green lights) in images. The goal is to recognize which of these objects appear in each image. You plan to use a deep neural network with ReLU units in the hidden layers.

Suppose that you use a sigmoid function for the output layer, and the output


has shape (5, 1). Which of the following best describes the cost function?