Please help me to solve this Algorithm question Show that 3n

Please help me to solve this Algorithm question

Show that 3n^3 +/2 - 17 = theta(n^3) Show that 2n^3 + 1 notequalto 0(n^2)

Solution

Ans.1. The dominating term is n^3. So the entire expression is always greater than n^3. Hence it is theta(n^3).

Ans.2. The dominating term is n^3. So it is always greater than the cube. Therefore, it is not O(n^2).