View of /trunk/NationalProblemLibrary/272/setStewart14_2/problem_5.pg

    1 ## DESCRIPTION
    2 ##   Continuity of Multivariable Function
    3 ## ENDDESCRIPTION
    4 
    5 ## KEYWORDS('Multivariable', 'Continuity')
    6 ## Tagged by nhamblet
    7 
    8 ## DBsubject('Calculus')
    9 ## DBchapter('Partial Derivatives')
   10 ## DBsection('Limits and Continuity')
   11 ## Date('')
   12 ## Author('')
   13 ## Institution('ASU')
   14 ## TitleText1('Calculus')
   15 ## EditionText1('')
   16 ## AuthorText1('Stewart')
   17 ## Section1('14.2')
   18 ## Problem1('')
   19 
   20 DOCUMENT();
   21 loadMacros("PG.pl",
   22            "PGbasicmacros.pl",
   23            "PGchoicemacros.pl",
   24            "PGanswermacros.pl",
   25            "PGauxiliaryFunctions.pl",
   26            "PGgraphmacros.pl",
   27            "Dartmouthmacros.pl");
   28 
   29 
   30 ## Do NOT show partial correct answers
   31 $showPartialCorrectAnswers = 0;
   32 
   33 $r = random(2, 20);
   34 
   35 @answers = (
   36             "\($LBRACE (x,y) | -x \le y \le x $RBRACE\)",
   37             "\($LBRACE (x,y) | -x < y < x $RBRACE\)",
   38             "\($LBRACE (x,y) | x \ge y $RBRACE\)",
   39             "\($LBRACE (x,y) | -x < y \le x $RBRACE\)",
   40             "the whole xy-plane",
   41             );
   42 @permutation = NchooseK(5,5);
   43 
   44 ## Ok, we are ready to begin the problem...
   45 ##
   46 TEXT(beginproblem());
   47 
   48 
   49 BEGIN_TEXT
   50 $BR
   51 
   52 The largest set on which the funtion \(f(x,y) = \sqrt{x+y} - \sqrt{x-y}\)
   53 is continuous is \{ans_rule()\}
   54 
   55 $PAR
   56 END_TEXT
   57 
   58 BEGIN_TEXT
   59      \{ (OL(@answers[@permutation])) \}
   60 
   61 END_TEXT
   62 
   63 @inverted_alphabet = @ALPHABET[invert(@permutation)];
   64 
   65 ANS(str_cmp($inverted_alphabet[0]));
   66 
   67 ENDDOCUMENT();
   68 
   69 
   70 
   71