CSCI 260 Fall 2016: Homework problems: Big Oh

Questions:

  1. Prove that n log n + log n ∈ O(n2).
  2. Prove using only the definition of Big-Oh (and appropriate use of "≤") that 17n2 log n - 60 ∈ O(n3)
  3. Prove using only the definition of Big-Oh that n2- n log n ∈ O(n2)
  4. Prove that if p(n) is a polynomial of degree k, then p(n) ∈ O(nk') for any k' ≥ k, where k and k' are positive real numbers. You can use the definition of big-Oh and any other big-Oh Rules in your proof, except the polynomail rule (which this is a version of).


  5. Show using the Rules of Big-Oh the following claim.

    Claim: 9n2log n + 9n log2n ∈ O(n2log n).

  6. Show using the Rules of Big-Oh, and/or using the definitions of Big-Oh and Θ, the following claim.

    Claim: (6n2)/log n ∈ Ω(n).

  7. Show using the Rules of Big-Oh, and/or using the definitions of Big-Oh and Θ, the following claim.

    Claim: It is not the case that (6n2)/log n ∈ O(n).

  8. Show using the Rules of Big-Oh, and/or using the definitions of Big-Oh and Θ, the following claim.

    Claim: 0.1 n4log n + 2n +1 ∈ Θ(n4log n).