Here's what's given: 3n + 2nlog2n + 5n^2 is O(n^2). I'm supposed to "base my justification on the mathematical definition of big-O."<br /><br />What I've done so far:<br /><br />We need to show that there are constants c and n0 (lowercase 0) such that 3n + 2nlog2n + 5n^2 <= cn^2<br /><br />n >= 1 and n^2 >= n<br /><br />Thus, it must be that 3n + 2nlog2n + 5n^2 <= [here's where I'm stuck]<br /><br />I don't know what to do with the 2nlog2n. I wanna substitute the brackets-part above with<br /><br />3n^2 + 2n^2log2n + 5n^2 but am pretty sure that's not right. I should be able to have a sum of all occurrences of n^2's but that log is tripping me up.<br /><br />I have two more questions that are related to big-O in a very similar way that I'm not sure about either. Any guidance would help <img src="http://static.dreamincode.net/forums/style_emoticons/default/smile.gif" style="vertical-align:middle" emoid="
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