Graph y = cos x for - x 2. On the same screen, graph for h = 1, 0.5, 0.3, and 0.1. Then,

Graph y = cos x for -π ≤ x ≤ 2π. On the same screen, graph

for h = 1, 0.5, 0.3, and 0.1. Then, in a new window, try h = -1, -0.5, and -0.3. What happens as h → 0⁺? As h → 0^-? What phenomenon is being illustrated here?

y = sin (x + h) - sin x h