Merge pull request #1227 from d-torrance/function-arithmetic

Convert function arithmetic problem to MathObjects

Author: gajennings

OpenProblemLibrary/ASU-topics/setAlgebraFunctions/srw2_8_1.pg

@@ -16,60 +16,47 @@ DOCUMENT();        # This should be the first executable line in the problem.
 
 loadMacros(
   "PGstandard.pl",
-  "PGchoicemacros.pl",
-  "PGcourse.pl"
+  "MathObjects.pl",
+  "PGcourse.pl",
 );
 
-TEXT(beginproblem());
-$showPartialCorrectAnswers = 1;
-
 $a = random(2,15,1);
 $b = random(1,15,1);
 
-TEXT(EV2(<<EOT));
-$BBOLD Note: $EBOLD For this question, input $BITALIC infinity $EITALIC 
-for \( \infty \)
-and input $BITALIC -infinity $EITALIC for \( -\infty \).
-$BR
-$BR
-Given that \(f(x)=x^2-$a x\) and \(g(x)=x + $b\), find
-$BR
-(a) \(f+g\)= \{ans_rule(25)\} and its domain is 
-(\{ans_rule(10)\}, \{ans_rule(10)\})
-$BR  
-(b) \(f-g\)= \{ans_rule(25)\} and its domain is 
-(\{ans_rule(10)\}, \{ans_rule(10)\})
-$BR  
-(c) \(fg\)= \{ans_rule(25)\} and its domain is 
-(\{ans_rule(10)\}, \{ans_rule(10)\})
-$BR  
-(d) \(f/g\)= \{ans_rule(25)\} and its domain is 
-\(x\not=\)\{ans_rule(10)\}
-$BR  
-EOT
-
-$ans1 = "x**2-($a-1)*x+$b";
-$ans2 = "-infinity";
-$ans3 = "infinity";
-$ans4 = "x**2-($a+1)*x-$b";
-$ans5 = "-infinity";
-$ans6 = "infinity";
-$ans7 = "(x**2-$a*x)*(x+$b)";
-$ans8 = "-infinity";
-$ans9 = "infinity";
-$ans10 = "(x**2-$a*x)/(x+$b)";
-$ans11 = -$b;
-ANS(fun_cmp($ans1));
-ANS(str_cmp($ans2));
-ANS(str_cmp($ans3));
-ANS(fun_cmp($ans4));
-ANS(str_cmp($ans5));
-ANS(str_cmp($ans6));
-ANS(fun_cmp($ans7));
-ANS(str_cmp($ans8));
-ANS(str_cmp($ans9));
-ANS(fun_cmp($ans10));
-ANS(num_cmp($ans11));
-
-ENDDOCUMENT();        # This should be the last executable line in the problem.
+$f = Formula("x^2 - $a x");
+$g = Formula("x + $b");
+
+Context("Interval");
+
+$R = Interval("R");
+
+BEGIN_TEXT
+
+$BBOLD Note: $EBOLD See \{helpLink("intervals")\} for help on entering intervals.
+$PAR
+
+Given that \(f(x)=\{$f->TeX\}\) and \(g(x)=\{$g->TeX\}\), find
+$PAR
+
+(a) \((f+g)(x)\)= \{ans_rule(25)\} and its domain is  \{ans_rule(10)\}
+$PAR
+
+(b) \((f-g)(x)\)= \{ans_rule(25)\} and its domain is \{ans_rule(10)\}
+$PAR
+
+(c) \((fg)(x)\)= \{ans_rule(25)\} and its domain is \{ans_rule(10)\}
+$PAR
+(d) \((f/g)(x)\)= \{ans_rule(25)\} and its domain is \{ans_rule(10)\}
+
+END_TEXT
+
+ANS(($f + $g)->cmp);
+ANS($R->cmp);
+ANS(($f - $g)->cmp);
+ANS($R->cmp);
+ANS(($f * $g)->cmp);
+ANS($R->cmp);
+ANS(($f / $g)->cmp);
+ANS(Interval("R - {-$b}")->cmp);
 
+ENDDOCUMENT();