Backpropagation: how it works

[@alexanderkorsunsky2792]

Thanks for the explanation! It's the clearest explanation I have found so far.

[@fukeya]

Really liked your short videos. Thanks!

[@dimitrab6485]

Amazing video... simple and yet not oversimplified. Thank you very much for uploading.

[@minecraftermad]

what exactly does a node do with for example 4 inputs? does it add them together and divide by 4 then multiply by a number? what do the weights do? is it something you do to the input number or does it tell the node something?

[@hosseinpourghaemi4600]

Undoubtedly all of your videos are excellent and very comprehensible. It would be very nice if you could add some information about the topics that your cover in each videos So we can find right video easily. Thank you.

[@linkolinkampret7840]

Hossein Pourghaemi O

[@tommyunreal]

Thank you for video, it's was very easy to understand!

[@arahflorgallardo871]

Good day Sir. Can you please clarify your interpretation of the sigmoid function, 4:00 - 4:20? I can't hear it quite well. This vid helped me out too, thank you.

[@sen15recess]

Thank you so much!

[@MrAgreeandDisagree]

At 5:15 Victor says "f.k times u.jk is just one component of the sum that feeds into g.j, so I just need to differentiate". Could anyone explain that comment about differentiating? Why does that help us?

[@abdul11235]

how are weights of edges computed and how do we know them before hand ?

[@minecraftermad]

they are randomized until you get good luck and the program works how you want

[@kaleeswaranm2679]

randomly initialized. check gradient descent for more info.

[@RigatoniModular]

is dE/dhi outside or inside of the summation?

[@ahabonatv9365]

ok great

[@NisseOhlsen]

Thank you for the video. I'm sorry, I do not follow. If g = sigma(mu + sum (mu_k*h_k) then dg/d(h_k) = sigma'(h_k)*mu_k, which means that dg = sigma'(h_k)*mu_k * dh_k so dE/dg = (just inserting) dE/((sigma'(h)*mu_k * dh_k ) = 1/(sigma'(h_k)*mu_k * dh_k ) *dE/d(h_k), so NOT equal to (sigma'(h)*mu_k * dh_k ) *dE/d(h_k) ??

[@minecraftermad]

too bad i havent gotten to that state of mathematics in school yet