We continue our analysis of a function. Even though a function is increasing, it can do so in different ways. For example, consider the functions:
.
Though both these functions are increasing in their domains, their graphs have different nature. Geometrically, the graph of one of them is bending away from the -axis while that of the other is bending towards the -axis. More precisely, for , if we choose any two points in the domain and consider , the line joining then this line segment always stays above the graph of the function. The situation is opposite for the function , the line stays below the graph of the function.
is increasing, it can do so in different ways. For example, consider the functions: 
. 
-axis while that of the other is bending towards the 
-axis. More precisely, for 
, if we choose any two points 
in the domain and consider 
, the line joining 
then this line segment always stays above the graph of the function. The situation is opposite for the function 
, the line 
stays below the graph of the function. 
