title: Confused about big O of n^2 vs 2^n
body: <p>I read in a book that the following expression <code>O(2^n + n^100)</code> will be reduced to: <code>O(2^n)</code> when we drop the insignificant parts. I am confused because as per my understanding if the value of <code>n</code> is <code>3</code> then the part <code>n^100</code> seems to have a higher count of executions. What am I missing?</p>