Theorem 2.4.  Suppose that    and    are continuous at the point  .  Then the following functions are continuous at .  

            The sum   ,  

            The difference   ,  

            The product   ,  

            The quotient   ,  provided that  .

            The composition  ,  provided that    is continuous in a neighborhood of the point  .

Proof.

Proof of Theorem 2.4 is left as exercises in the book.

Complex Analysis for Mathematics and Engineering

(c) 2006 John H. Mathews, Russell W. Howell