Making the value of 'a' smaller, but still positive, will make the graph be compressed vertically.
Let's say a = 1 is the initial value. If we update it to a = 0.5, then the graph will be half as tall as it used to be, so it's compressed by a factor of 1/0.5 = 2.
The value of b determines the period of the sinusoidal function.
