Logo Data Structures and Algorithms with Object-Oriented Design Patterns in C++
next up previous contents index

A Simple Example

Consider the function tex2html_wrap_inline59933 which is shown in Figure gif. Clearly, f(n) is non-negative for all integers tex2html_wrap_inline59063. We wish to show that tex2html_wrap_inline59939. According to Definition gif, in order to show this we need to find an integer tex2html_wrap_inline59043 and a constant c>0 such that for all integers tex2html_wrap_inline59075, tex2html_wrap_inline59947.

As with big oh, it does not matter what the particular constants are--as long as they exist! E.g., suppose we choose c=1. Then

eqnarray1662

Since tex2html_wrap_inline59951 for all values of tex2html_wrap_inline59063, we conclude that tex2html_wrap_inline59955.

So, we have that for c=1 and tex2html_wrap_inline59955, tex2html_wrap_inline59947 for all integers tex2html_wrap_inline59075. Hence, tex2html_wrap_inline59939. Figure gif clearly shows that the function tex2html_wrap_inline59115 is less than the function f(n)=5n-64n+256 for all values of tex2html_wrap_inline59063. Of course, there are many other values of c and tex2html_wrap_inline59043 that will do. For example, c=2 and tex2html_wrap_inline59103.

   figure1665
Figure: Showing that tex2html_wrap_inline60011.


next up previous contents index

Bruno Copyright © 1997 by Bruno R. Preiss, P.Eng. All rights reserved.