Exercise 7.  Prove that  .  

Solution 7.

See text and/or instructor's solution manual.

Let  .  

Then   

iff     

iff     

iff     

iff    

iff    

iff    

iff    ,   which is clearly true.  

A proper argument will start with this last inequality and work backwards to the appropriate conclusion.

This solution is complements of the authors.

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