Merge pull request openwebwork#594 from jirilebl/tomo

Change a problem to MathObjects to improve output

OpenProblemLibrary/Michigan/Chap20Sec2/Q37.pg

@@ -68,7 +68,7 @@ surface per unit of time.
 
 $PAR
 ${BBOLD}(a)$EBOLD
-Suppose that the actual heat generation is \($r \mbox{W}/\mbox{km}^3\)
+Suppose that the actual heat generation is \($r \mbox{W}/\mbox{km}^3\).
 What is the value of \(\mbox{div }\vec F \)?
 $BR
 \(\mbox{div }\vec F = \) \{ ans_rule(25) \}

OpenProblemLibrary/Rochester/setVectorCalculus3/ur_vc_13_3.pg

@@ -10,6 +10,7 @@
 ## Date(6/3/2002)
 ## MLT(Divergence_sphere_constant_div)
 ## Level(2)
+## MO(1)
 ## TitleText1('Calculus: Early Transcendentals')
 ## AuthorText1('Stewart')
 ## EditionText1('5')
@@ -29,6 +30,7 @@ DOCUMENT();		# This should be the first executable line in the problem.
 loadMacros(
   "PGstandard.pl",
   "PGchoicemacros.pl",
+  "MathObjects.pl",
   "PGcourse.pl"
 );
 
@@ -40,15 +42,22 @@ $b = random(1, 5, 1);
 $c = random(1, 5, 1);
 $d = $a**2;
 
+Context("Vector");
+
+$v = Compute("-y*i+x*j+$b*z*k")->reduce;
+$ans = Compute("(4*$b*$c*$d*$a*pi)/3");
+
+Context()->texStrings;
 BEGIN_TEXT
 A fluid has density $c and velocity field 
-\( \mathbf{v} = -y\mathbf{i} + x\mathbf{j} + $b\!z\mathbf{k} \).$BR
+\( \mathbf{v} = $v \).$PAR
 Find the rate of flow outward through the sphere 
-\( x^{2} + y^{2} + z^{2} = $d \)
+\( x^{2} + y^{2} + z^{2} = $d \):
 $PAR
 \{ ans_rule(40) \}
 END_TEXT
+Context()->normalStrings;
 
-ANS(num_cmp( (4*$b*$c*$d*$a*3.14159)/3 ) );
+ANS($ans->cmp());
 
 ENDDOCUMENT();		# This should be the last executable line in the problem.