Definition of local maximum and local minimum :
\1. The number 
 is a local maximum value of 
 if 
 when 
 is near 
.
2.The number 
 is a local minimum value of 
 if 
 when 
 is near 
.
Definition of absolute maximum and absolute minimum :
\Let 
 be a number in the domain 
 of a function 
.
1.The number 
 is a absolute maximum value of 
 on 
 if 
 for all 
 in 
.
2.The number 
 is a absolute minimum value of 
 on 
 if 
 for all 
 in 
.
The function is 
, 
.
Construct a table for different values of 
 :
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Graph :
\1) Draw the co-ordinate plane.
\2) Plot the points.
\3) Connect the points with a smooth curve.
\.gif\")
Observe the graph.
\The range of cosine function is 
.
Since 
 when 
 is near 
, local minimum is 
.
Since 
 when 
 is near 
, local minimum is 
.
Since 
 on its domain 
, absolute minimum is 
.
Since 
 on its domain 
, absolute minimum is 
.
Since 
 when 
 is near 
, local maximum is 
.
Since 
 on its domain 
, absolute maximum is 
.
Graph of the function 
 :
.gif\")
Absolute and local minimum :  
 and 
.
Absolute and local maximum : 
.