8. Suppose that ho, hi, h2, is a sequence defined as fol lows: hk - hk-i +hk-2 + hk-3 for all integers k 2 3 a. Prove that hn s 3" for all integers n 2 0 b. Suppose that s is any real number such that s3 s2 s+1. (This implies that s > 1.83.) Prove that h