(D) See Figure N2–1.(E) Note, from Figure N2–1, that .(E) As x → ∞, the function sin x oscillates between −1 and 1; hence the
limit does not exist.(A) Note that and that .(A).(E) Verify that f is defined at x = 0, 1, 2, and 3 (as well as at all other
points in [−1,3]).(C) Note that . However, f (2) = 1. Redefining f (2) as
0 removes the discontinuity.(B) The function is not continuous at x = 0, 1, or 2.(B).