4. Your company is experiencing financial difficulties, which has resulted in a hir- ing freeze. Because of limited support- staff positions and internships, upper- management personnel will now have to do more of their own office tasks, such as photocopying and typing correspond- ence. First, consider the possible reactions and feelings regarding the change in re- sponsibilities. Then write a memo from the human-resources department to upper management, describing the situation and explaining the new policy. Practice Questions __Bigo_Omega_Theta Prove the Big-O estimates for the following function f(n) 1. f(n) = 3n2 + 7n + 2 is O(n) 2. f(n) = 4n3 6n2 + 3n - 4 is O(n3) 3. f(n) = 5n* +4n3 3n2+1 is O(n^)