The tanh function

Tanh is a continuous function symmetric around the origin; it ranges from -1 to 1. The tanh function is represented as follows:

Thus the output signals will be both positive and negative thereby, adding to the segregation of the signals around the origin. As mentioned earlier, it is continuous and also non linear plus differentiable at all points. We can observe these properties in the graph of the tanh function in the following diagram. Though symmetrical, it becomes flat beyond -2 and 2:

Now looking at the gradient curve of the following tanh function, we observe it being steeper than the sigmoid function. The tanh function also has the vanishing gradient problem: