Sigmoid Function

Hello all,
Sigmoid Function or Logistic Function , it is used in Machine Learning problems for the purpose of learning (Neural network ) on curves.
its range between ]0,1[ it is horizontal asymptotic on 0 and 1, because of its range between 0 and 1 it is used in classification using threshold for example if we take 0.5 as a threshold values greater than 0.5 are considered Ones and values less than or Equal 0.5 considered 0.

it has the following formula :

and it shape as following :

from wikipedia

so it accept differentiation over its domain unlike Step Function.

differentiation of sigmoid function :

I finished the article , i hope you understand it .

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