# Model Representation ll

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Model Representation ll
• how to do it efficiently (vectorized)
• why neural networks works,  how is it a good idea

• rename the content of g as z
• g is sigmoid function of multiplication wise element of z
• remember that a1 is units in layer 1
• a3 is  the final unit for hypothesis
• the computation of formula written on the right side is the simple way if calculating h of x.