In the optional lab, I noticed
βNote, the orange line is βπ§β or π°β π±(π)+π above. It does not match the line in a linear regression model.β

Itβs unclear to me why wx + b would be different than what we get in the linear regression model. Isnβt z nothing but the linear regression model?

Sigmoid is used on top of the z function, right? So, g(z) is the sigmoid, but z itself should be an affine function and therefore same as what you get via linear regression.

For one issue, when you need the gradients of the logistic function, you have to deal with the partial derivative of the sigmoid function. Thatβs a bit more complicated than just the partial derivative of z = w*x + b (whose derivative is just βwβ).