### 2018 exam problem 7

Hi, TA. I would like to ask why the partial derivative of w1 is not changed, I did not understand the answer.

Up

Up again! Would like an answer to this one too. :)

up

The partial derivative is defined as dL/dw1 for the given operating point. Saying w2=w3 in weight sharing just means that dL/dw2 and dL/dw3 is really 1+1=2 sicne you can't change one of the parameters without also changing the other. But w1 isn't sharing weights with any other so it keeps the original found partial derivative of 1