This work is, broadly speaking, a revised edition and
Increased text due to Professor Grall \ 'ille. The only changes
introduced are reduced to small details in the demonstrations, to
reviewing the issues - adding some application to the
Economics and other extras at the end of each chapter for more students
advantages- and the writing of a chapter on Hyperb6 functions-
licas, along with some application patterns of cylindrical fillings in double integrals.
The work of the authors of this edition. It will be widely thought of if the first edition of the