1. (a) Let n > 0. Prove that 1/ n+1 < ln (n + 1) - ln n < n (1/n) b. Define the sequence {an} as an = (1+ 1/2 + 1/3 +... + 1/n) - In n. Show that {an} is decreasing and an ≥ 0 for all n. Is {an} convergent? Explain.