I know the first one is theta and the second one is omega,but I don't know how to prove that. Can someone help me and show the step of proof?

4. (8 points) Indicate for each of the following pairs of expressions (f(n), g(n)), whether f(n) is 0.0, or of g(n). Prove your answers to the first two items, but just GIVE an answer to the last two. (a) f(n) 410g4 n and g(n)-2T + 1. Answer for (a):f(n) (b) f(n) n2 and g(n) -(V2)lo2n log2 n Answer for (b):f(n)g(n)