The exercise asks us to prove 3^n >= n^3 for n >= 4.
However in the answer you use 3^n > n^3 instead of 3^n >= n^3.
since if 3^n > n^3 is true then 3^n >= n^3 is also true so the answer isn't wrong. But I wonder if this was intentional or is there some specefic reason you used > instead of >=.
