limit questions

[starchild75]

1. The problem statement, all variables and given/known data

find the value of k such that the limit exists. lim xgoes to infinity (x^3-6)/(x^k+3).


2. Relevant equations



3. The attempt at a solution

I multiply both sides by 1/x^3 I get 1 in the numerator and x^k/x^3 in the denominator. I don't know what to next.

[Dick]

x^k/x^3 is x^(k-3). Consider the cases of k>3, k<3 and k=3.