Deep Learning - Deep Neural Network for Beginners Using Python - Sigmoid Function Implementation

The video tutorial introduces the sigmoid function, providing its definition and formula. It then discusses the implementation approach, highlighting a conventional change from using Z to X as a variable. The tutorial proceeds to define the sigmoid function in code, explaining the return statement that uses the numpy exponential function.

What is the mathematical definition of the sigmoid function as mentioned in the text?

Why is the variable 'X' used instead of 'Z' in the implementation of the sigmoid function?

How does the sigmoid function relate to the concept of feature vectors in machine learning?

What does the sigmoid function return when given a feature vector?

Explain the role of the Numpy dot exponential in the sigmoid function implementation.