Slog 9

In this week’s lecture, we did several proves about the O(n^2) and Ω(n^2). First we did the prove about 3n^2 + 2n ∈ O(n^2). It was easy after seeing the answer; however the second question was really hard that I did not get it until I read the answer for several times. The second question is 7n^6 -5n^4 +2n^3∈ O(6n^8-4n^5+n^2). We need to make both (7n^6 -5n^4 +2n^3) and (6n^8-4n^5+n^2) as big as possible. So the value of c should be 4.5.The next type of question about disprove. The example is n^3∉O(3n^2). 

The next part of the lecture is about non-polynomials. We can use the limit function to solve non-polynomials. It totally confused. I hope I could do better in the next lecture.