# Understand Sigmoid Function: Properties and Derivative – Machine Learning Tutorial

By | September 21, 2020

Sigmoid function is often used as an activation function in neural network. In this tutorial, we will introduce the properties and derivative of this function.

## What is sigmoid function?

The equation of sigmoid function is:

The graph of sigmoid function is:

## The properties of sigmoid function

There are some important properties, they are:

1. The value range

2.

## The derivative of the sigmoid function

The derivative is:

The graph of derivative is:

## How to compute sigmoid value?

In tensorflow, we can use tf.sigmoid() function to compute the sigmoid value of a tensor. Here is the tutorial:

Compute sigmoid value of a Tensor with tf.sigmoid – TensorFlow Math Function