Exercise 20.  Many texts give an alternative definition for  ,  starting with (5-1) as the definition for  .  

20 (b).  Show that the result in part (a) implies that  .

This means    is constant with respect to x, so  ,  where is a function of y alone.

Solution 20 (b).

See text and/or instructor's solution manual.

Solution.   From part (a)   ,  hence

                       

This means    is constant with respect to x, so  ,  where is a function of y alone.

This solution is complements of the authors.

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