Section 1.2

When finding a limit (one-sided or two-sided) as x approaches a number:

  1. First try plugging in for x the number x is approaching. If this gives you a number, then that will be your answer.
Exception:


  1. If plugging in the number x is approaching causes your denominator to be zero and your numerator to be something other than zero, then your answer is either infinity , negative infinity, or both, in which case you write d.n.e. To determine which, examine the sign of the numerator and denominator.

  2. If plugging in the number x is approaching causes both the numerator and denominator to equal zero, then try one of the following:

    factoring, getting rid of complex fractions, removing absolute value, or rationalizing fractions containing expressions such as .

If you missed class, you can watch my online movies. You must have QuickTime Player, a free download, installed on your computer.
Finding two-sided limits is movie 3 on this page.
Finding one-sided limits is movie 2 on this page.

More help:
Evaluating limits from www.calculus-help.com