How  can you create a loop for Monty Hall Problem when you have 3 door (1 opening) and then 4 Doors (with 2 openings and possible 2 switches)

Hi, I need to show some how by using Maple, that n^3>(n+1)^2 where n>=3. Iam new at Maple and not sure how I can graph inequality as n goes to infinity. Any help would be appriciated. Thanks!!!