Example 3.  Plot the absolute error  [Graphics:Images/NumericalDiffMod_gr_91.gif]  over the interval  [Graphics:Images/NumericalDiffMod_gr_92.gif],  and estimate the maximum absolute error over the interval.
3 (a).  Compute the error bound  [Graphics:Images/NumericalDiffMod_gr_93.gif]  and observe that  [Graphics:Images/NumericalDiffMod_gr_94.gif]  over  [Graphics:Images/NumericalDiffMod_gr_95.gif].  
3 (b).  Since the function f[x] and its derivative is well known, and we have the graph for [Graphics:Images/NumericalDiffMod_gr_96.gif],  we can observe that the maximum error on the given interval occurs at x=0.  Thus we can do better that "theory", we see that [Graphics:Images/NumericalDiffMod_gr_97.gif]  over  [Graphics:Images/NumericalDiffMod_gr_98.gif].

Solution 3.

3 (a).  Compute the error bound  [Graphics:../Images/NumericalDiffMod_gr_99.gif]  and observe that  [Graphics:../Images/NumericalDiffMod_gr_100.gif]  over  [Graphics:../Images/NumericalDiffMod_gr_101.gif].  

[Graphics:../Images/NumericalDiffMod_gr_102.gif]


[Graphics:../Images/NumericalDiffMod_gr_103.gif]

[Graphics:../Images/NumericalDiffMod_gr_104.gif]
[Graphics:../Images/NumericalDiffMod_gr_105.gif]
[Graphics:../Images/NumericalDiffMod_gr_106.gif]
[Graphics:../Images/NumericalDiffMod_gr_107.gif]
[Graphics:../Images/NumericalDiffMod_gr_108.gif]

3 (b).  Since we the function f[x] and its derivative is well known, and we have the graph for [Graphics:../Images/NumericalDiffMod_gr_109.gif],  we can observe that the maximum error on the given interval occurs at x=0.  Thus we can do better that "theory", we see that [Graphics:../Images/NumericalDiffMod_gr_110.gif]  over  [Graphics:../Images/NumericalDiffMod_gr_111.gif].

[Graphics:../Images/NumericalDiffMod_gr_112.gif]


[Graphics:../Images/NumericalDiffMod_gr_113.gif]

[Graphics:../Images/NumericalDiffMod_gr_114.gif]
[Graphics:../Images/NumericalDiffMod_gr_115.gif]
[Graphics:../Images/NumericalDiffMod_gr_116.gif]
[Graphics:../Images/NumericalDiffMod_gr_117.gif]

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(c) John H. Mathews 2004