Merge pull request #1022 from gajennings/main

Update problem to accept varied forms of correct answers

Author: gajennings

OpenProblemLibrary/UCSB/Stewart5_10_2/Stewart5_10_2_30.pg

@@ -17,38 +17,34 @@ DOCUMENT();
 loadMacros(
   "PGstandard.pl",
   "MathObjects.pl",
+  "parserImplicitPlane.pl",
   "PGcourse.pl"
 );
 
-TEXT(&beginproblem);
+TEXT(beginproblem());
+
 $showPartialCorrectAnswers = 1;
 
-Context("Numeric");
+Context("ImplicitPlane");
+Context()->variables->are(x => Real, y => Real);
 
-$ans1 = Compute("-2x+11");
-$ans2 = Compute("x-1");
+$ans1 = ImplicitPlane("y=-2x+11");
+$ans2 = ImplicitPlane("y=x-1");
+$ans = List($ans1,$ans2);
 
 Context()->texStrings;
 BEGIN_TEXT
 
 Find an equation for each line that passes through the point (4, 3) and is tangent to the parametric curve
 \[x=3t^2+1,\;\;y=2t^3+1.\]
-If there is more than one answer then order your answers consecutively so lines with smaller slopes appear before lines with larger slopes. If some answer fields are not used enter $BBOLD None $EBOLD in the unused answer blanks and list them last.
-
-$PAR
-Tangent line 1: \(y\) = \{ans_rule(25)\}
-
-$PAR
-Tangent line 2: \(y\) = \{ans_rule(25)\}
+If there are multiple answers then separate distinct answers with commas.
 
 $PAR
-Tangent line 3: \(y\) = \{ans_rule(25)\}
+\{ans_rule()\}
 
 END_TEXT
 Context()->normalStrings;
 
-ANS($ans1->cmp());
-ANS($ans2->cmp());
-ANS(List('None')->cmp());
+ANS($ans->cmp());
 
 ENDDOCUMENT();