Original statement:

$\displaystyle f(n)=(n^3+4log_2 n)/(n+4)$

I'm sure the n+4 in both the denominator and numerator have something to do with it, but if i make $\displaystyle n$in the denominator a $\displaystyle n^3$, wouldn't that then make it smaller the the LHS?

I'm suppose to prove

$\displaystyle f(n)=0(n^2)$

which means i need the inequality to make the RHS bigger than the LHS