Graph the function y = 2cos2x for -2 ≤ x ≤ 3.5. Then, on the same screen, graph

for h = 1.0, 0.5, and 0.2. Experiment with other values of h, including negative values. What do you see happening as h → 0? Explain this behavior.

y = sin 2(x + h) - sin 2x h