Merge pull request #1179 from lahvak/fix_graph_window

Prevent a point on a graph being placed on the edge of window with invisible label

OpenProblemLibrary/Rochester/setAlgebra28ExpFunctions/ur_le_1_5.pg

@@ -20,6 +20,7 @@ DOCUMENT();        # This should be the first executable line in the problem.
 
 loadMacros(
   "PGstandard.pl",
+  "PGML.pl",
   "PGchoicemacros.pl",
   "PGgraphmacros.pl",
   "PGnumericalmacros.pl",
@@ -30,8 +31,7 @@ TEXT(beginproblem());
 $showPartialCorrectAnswers = 1;
 
 $a = random(2,5,1);
-$y = random(2,5,1);
-if ($y == $a) {$y = $y+1;}
+do {$y = random(2,5,1);} until ($y != $a);
 $s = random(-1,1,2);
 $b = ln($y/$a)/ln(2);
 $a = $a*$s;
@@ -48,19 +48,15 @@ add_functions($graph1, $fn, $pt0, $pt1);
 $label_0 = new Label ( 0.5,$a,"(0,$a)",'black','left','middle'); $graph1->lb($label_0);
 $label_1 = new Label ( 1.5,$y,"(1,$y)",'black','left','middle'); $graph1->lb($label_1);
 
-BEGIN_TEXT
+BEGIN_PGML
+Find the exponential function [`f(x)=a\cdot 2^{b x}`] whose graph is shown below
 
-Find the exponential function \(f(x)=a\cdot 2^{b x}\) whose graph is shown below
-$BR
-\{ image(insertGraph($graph1), width=>200, height=>200) \}
-$BR
-\(a=\) \{ans_rule(20)\} $BR
-\(b=\) \{ans_rule(20)\} 
+[!Graph of exponential function passing through points (0,[$a]) and (1,[$y])!]{$graph1}{width=>200, height=>200}
 
-END_TEXT
+* [`a=`][____________________]{$a}
+* [`b=`][____________________]{$b}
 
-ANS(num_cmp($a));
-ANS(num_cmp($b));
+END_PGML
 
 ENDDOCUMENT();       # This should be the last executable line in the problem.