Please give full detailed explanation please

4. Answer the following questions by a proof or dis-proof. 4.1. What is the big-O estimate for f(n) = 87 log|(3n) + 2n2 log3(7n2) + 4n3 V + 7 ? 4.2. What is the big- estimate for f(n) = 4n+ + 2nvn log?(n) +11n3 vn log2 (2n) - 11n +3 ? 4.3. Is f(n) = 13n +onyn log(3n?) - 4n log (5n+) + 2n - 1 in N(n?)? Is f(n) in 0(n?)? Is f(n) in N(n?)