I'm dealing with calculation in terms of Big Oh or Theta notations.

For example,

If I want to simplify O(n^k * sqrt ( a* n^m - n^p )) as much as possible, where a is positive constant and k,m,p are positive unknown, then is it possible for me to remove the term n^p?

Then, the final answer is O(n^k * sqrt (n^m)). Is this correct?