Exercise 7.  Suppose that the sequences of functions  [Graphics:Images/UniformConvergenceModHome_gr_265.gif]  and  [Graphics:Images/UniformConvergenceModHome_gr_266.gif]  converge uniformly on the set  T.  

7 (a).  Show that the sequence  [Graphics:Images/UniformConvergenceModHome_gr_267.gif]  converges uniformly on the set  T.  

Solution 7 (a).

See text and/or instructor's solution manual.

Solution.   Let us say that  [Graphics:../Images/UniformConvergenceModHome_gr_268.gif]  converge uniformly on  T  to  [Graphics:../Images/UniformConvergenceModHome_gr_269.gif]  respectively.  

Let  [Graphics:../Images/UniformConvergenceModHome_gr_270.gif]  be given.   

The uniform convergence of  [Graphics:../Images/UniformConvergenceModHome_gr_271.gif]  means there exists an integer  [Graphics:../Images/UniformConvergenceModHome_gr_272.gif]  such that  [Graphics:../Images/UniformConvergenceModHome_gr_273.gif]  implies  

                    [Graphics:../Images/UniformConvergenceModHome_gr_274.gif]    for all   [Graphics:../Images/UniformConvergenceModHome_gr_275.gif].  

Likewise, there exists an integer  [Graphics:../Images/UniformConvergenceModHome_gr_276.gif]  such that  [Graphics:../Images/UniformConvergenceModHome_gr_277.gif]  implies  

                    [Graphics:../Images/UniformConvergenceModHome_gr_278.gif]    for all   [Graphics:../Images/UniformConvergenceModHome_gr_279.gif].  

If we set  [Graphics:../Images/UniformConvergenceModHome_gr_280.gif],  then for  [Graphics:../Images/UniformConvergenceModHome_gr_281.gif],

                    [Graphics:../Images/UniformConvergenceModHome_gr_282.gif]     

for all   [Graphics:../Images/UniformConvergenceModHome_gr_283.gif].  

Therefore,  [Graphics:../Images/UniformConvergenceModHome_gr_284.gif]  converges uniformly to  [Graphics:../Images/UniformConvergenceModHome_gr_285.gif]  on the set  T.  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

This solution is complements of the authors.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(c) 2008 John H. Mathews, Russell W. Howell