Starting from b=1, what happens to the shape of the function f(x) as b becomes more positive?
What happens to the shape of f(x) as b decreases and passes through zero to the negatives?

Press the second button down so you every integer multiple of pi.
For different integer values of b, how many times does the function f(x) cross the x-axis before intersecting a multiple of pi?
Does this change as you vary the amplitude a?