Page 9 - Calc for the Clueless
P. 9

Important Note 1

        Anytime the degree of the top is less than the degree of the bottom, the limit will be 0. You need not do the
        work (unless the teacher demands it). You should know that the limit is 0!!!!!!

        Example 11—






        If we could talk about a degree of the top, it would be 5/2, or 2½. Since the degree of the bottom is 3, which is
        more than the top, the limit is 0!

        Example 12—


                                                                 3
                                              Divide everything by x .




        We get






        If we now let x go to infinity, we get the limit to be 4/-3 or-4/3.

        Important Note 2

        If the degree of the top is the same as the degree of the bottom, the limit is the coefficient of the highest power
        on the top divided by the coefficient of the highest power on the bottom. Again, you do not actually have to do
        the division.

        Here are two more limits as x goes to infinity.

        Example 13—





        We get infinity minus infinity. No good!!! What to do? We rationalize the situation. Seriously, we multiply top
        and bottom by the conjugate.






        So we get






        Example 14, Part A—






        Example 14, Part B—
   4   5   6   7   8   9   10   11   12   13   14