Wednesday, 13 February 2013

Limits at Infinity



Vocabulary
limit at infinity, infinite limit, horizontal asymptote, indeterminate expression, infinite limit at infinity
Objectives
                1. Explain what is meant by equations such as  or  .
                2. Recognize indeterminate expressions.
                3. Sketch the graph of a function with specified limit conditions.
                4. Find the value of certain limits at infinity and infinite limits.
                5. Determine the horizontal and vertical asymptotes of a given function.
Lecture Outline
In this section we consider the end behavior of functions. That is, we examine the behavior of  as  increases without bound or decreases without bound.
Definition of Limit at Infinity
Let  be a function which is defined on some interval (  ). Then  means that the values of  can be made arbitrarily close to  by taking  sufficiently large.
Often when  is a rational function, the graph of  will behave like a line as  increases or decreases without bound. When this happens, the line which the graph of  approaches is called a horizontal asymptote .