LO 2.2.3.C

Learning Objective: Learning Objective: Calculate the output of a sigmoid function, which is also referred to as a logistic function.

Review:

 

<math xmlns="http://www.w3.org/1998/Math/MathML"><mi>&#x3C3;</mi><mfenced><mi>z</mi></mfenced><mo>=</mo><mfrac><mn>1</mn><mrow><mn>1</mn><mo>+</mo><msup><mi>e</mi><mrow><mo>-</mo><mi>z</mi></mrow></msup></mrow></mfrac></math>

where  is the activation function

 <math xmlns="http://www.w3.org/1998/Math/MathML"><munder><mrow><mi>Z</mi><mo>=</mo><mo>&#x2211;</mo></mrow><mrow/></munder><msub><mi>w</mi><mi>j</mi></msub><msub><mi>x</mi><mrow><mi>j</mi><mo>&#xA0;</mo></mrow></msub><mo>+</mo><mi>b</mi><mi>i</mi><mi>a</mi><mi>s</mi></math>