title: How to find upper bound of function
body: <p>How to find the upper bound (Big O) for f(n) = 2n^3-2n^2. Want to know the C and n.</p>
  
  <p>I tried below.</p>
  
  <ol>
  <li><p>f(n)&lt;=C*g(n)</p></li>
  <li><p>2n^3-2n^2 &lt;= C*n^3</p>
  
  <p>My understanding of finding "C" is, consider only higher polynomial degree. So..</p></li>
  <li><p>2n^3 &lt;= C*n^3 ---> (omitted 2n^2)</p></li>
  <li>Thus arrived the value of C as 3. </li>
  </ol>
  
  <p>But the answer given in my book is C = 2.</p>
  
  <p>question 1: Please clarify how C will be 2.</p>
  
  <p>question 2: how to find the value of n.</p>