Fix bug 4688

Author: gajennings

OpenProblemLibrary/AlfredUniv/diffeq/series/differentiateseries.pg

@@ -11,6 +11,8 @@
 ## Institution(Alfred University)
 ## Author(Darwyn Cook)
 ## Level(2)
+## MO(1)
+## Static(1)
 ## TitleText1('Differential Equations: With Boundary Value Problems')
 ## AuthorText1('Zill')
 ## EditionText1('6')
@@ -33,7 +35,7 @@ $showPartialCorrectAnswers = 1;
 Context()->variables->add(k=>"Real");
 
 $ak = Formula("(k+1)x^(k+3)");
-$derivative = $ak->D('x');
+$derivative = $ak->D('x')->with(limits=>[[1,2],[1,2]]) ;
 
 Context()->texStrings;
 BEGIN_TEXT