Fix bug 4650

Author: gajennings

OpenProblemLibrary/UMN/algebraKaufmannSchwitters/ks_13_4_2.pg

@@ -25,23 +25,18 @@ DOCUMENT();
 loadMacros(
   "PGstandard.pl",
   "MathObjects.pl",
-  "parserAssignment.pl",
-  "answerCustom.pl",
-  "weightedGrader.pl",
+  "parserImplicitPlane.pl",
   "PGcourse.pl"
 );
 ##############################################################
 
-install_weighted_grader();
-
 TEXT(beginproblem());
 
-$showPartialCorrectAnswers = 0;
+$showPartialCorrectAnswers = 1;  
 
 ##############################################################
 
-Context("Numeric")->variables->add(y=>'Real');
-parser::Assignment->Allow;
+Context("Point");
 Context()->strings->add(none=>{},EmptySet=>{alias=>"none"});
 
 $a = random(2,4,1);
@@ -57,11 +52,16 @@ $an1b = Point(-$a,0);
 $an2a = Point($c,0);
 $an2b = Point(-$c,0);
 
-$an3a = Formula("y=($b/$a)*x");
-$an3b = Formula("y=-($b/$a)*x");
-
 $ans1 = List($an1a, $an1b);
 $ans2 = List($an2a, $an2b);
+
+Context("ImplicitPlane");
+Context()->variables->are(x=>'Real',y=>'Real');
+Context()->strings->add(none=>{},EmptySet=>{alias=>"none"});
+
+$an3a = ImplicitPlane("y=($b/$a)*x");
+$an3b = ImplicitPlane("y=-($b/$a)*x");
+
 $ans3 = List($an3a, $an3b);
 
 ##############################################################
@@ -76,16 +76,17 @@ Answer (separate by commas): \{ans_rule(30)\} $PAR
 $BBOLD 2.$EBOLD Find the foci. $BBOLD List your answers as points in the form \((a,b)\). $EBOLD $BR
 Answer (separate by commas): \{ans_rule(30)\} $PAR
 $BBOLD 3.$EBOLD Find the equations of the asymptotes. $BR
-Equation(s) (in slope-intercept form \(y=mx+b\) and separate by commas):  \{ans_rule(30)\} 
+(Separate equations by commas):  \{ans_rule(30)\} 
 $BR
 END_TEXT
 Context()->normalStrings;
 
 ##############################################################
 
-Context("Numeric");
-WEIGHTED_ANS( ($ans1)->cmp(showHints=>0,showTypeWarnings=>0), 33 );
-WEIGHTED_ANS( ($ans2)->cmp(showHints=>0,showTypeWarnings=>0), 33 );
-WEIGHTED_ANS( ($ans3)->cmp(showHints=>0,showTypeWarnings=>0, showEqualErrors=> 0), 34 );
+
+ANS( $ans1->cmp());
+ANS( $ans2->cmp());
+ANS( $ans3->cmp());
+
 
 ENDDOCUMENT();