Notice that the changing values of a and b have the same effect
that they had on the graphs involving the cosine function. However,
as we change the value of k, the amount of rotation of the two
graphs appears to change. for the first example where k=1, the
rotation is clearly 90 degrees (or radians).
For k=2, the rotation appears to be 45 degrees (
radians). As the value of k increases, it appears as though the
angle of rotation is shrinking. If we think a bit about our knowledge
of trigonometry, we can show that the angle of rotation for each
of these graphs is
radians or
degrees.