Exercise 5.  Why can't we use the arguments of Theorem 7.2 to prove that the geometric series  [Graphics:Images/UniformConvergenceModHome_gr_240.gif]  converges uniformly on all of  [Graphics:Images/UniformConvergenceModHome_gr_241.gif]?  

Solution 5.

See text and/or instructor's solution manual.

Solution.   The crucial step in the proof of Theorem 7.2 is the statement, "Moreover, for all  [Graphics:../Images/UniformConvergenceModHome_gr_242.gif]  it is clear that  

            [Graphics:../Images/UniformConvergenceModHome_gr_243.gif].     

Applying Theorem 7.2 we write   [Graphics:../Images/UniformConvergenceModHome_gr_244.gif]  and here we have  [Graphics:../Images/UniformConvergenceModHome_gr_245.gif]  for all  n,  and  [Graphics:../Images/UniformConvergenceModHome_gr_246.gif].  

If we set  [Graphics:../Images/UniformConvergenceModHome_gr_247.gif],  then   [Graphics:../Images/UniformConvergenceModHome_gr_248.gif]  does not converge.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

This solution is complements of the authors.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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