In the Sigmoid function video. How is there an equivalence between f(x) and g(wx+b)?

Course Q&A Machine Learning Specialization Supervised ML: Regression and Classification
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Hi @Sparsh22 ,

This is to say the transformation of f(x) with weights w and b gives an output z.
When applying the sigmoid function to z, that becomes g(z).
given the formula for sigmoid is 1/1+e^-(^z), and we know that z = wx+b, so we just substitute z with wx+b in the sigmoid formula.

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They are equivalent because that’s where we are defining f_wb.

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@Sparsh22

You can also take a look here, where we discuss the similar topic.

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Hi, @Sparsh22 .

f(x) is the input of g(z) , i.e z=f(x)=wx+b.