Look at the graph below, try to slide the value of 'a' to different values to view the changes on graph.
Now, take a look at the graph of the reciprocal of hyperbolic cosine function, i.e. hyperbolic secant function, which is defined as
Observe that when a = 1,
Again, slide the value of 'a' to view the changes of the graph.
Betty, Created with GeoGebra