--- loncom/xml/lontexconvert.pm	2016/02/20 00:12:45	1.118
+++ loncom/xml/lontexconvert.pm	2017/10/07 00:50:57	1.120
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # TeX Conversion Module
 #
-# $Id: lontexconvert.pm,v 1.118 2016/02/20 00:12:45 raeburn Exp $
+# $Id: lontexconvert.pm,v 1.120 2017/10/07 00:50:57 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -331,7 +331,12 @@ sub tex_engine {
         }
 	return $env{'environment.texengine'};
     }
-    return 'tth';
+    my $dom = $env{'request.role.domain'} || $env{'user.domain'};
+    my %domdefaults = &Apache::lonnet::get_domain_defaults($dom);
+    if ($domdefaults{'texengine'} ne '') {
+        return $domdefaults{'texengine'};
+    }
+    return 'MathJax';
 }
 
 sub init_math_support {
@@ -548,7 +553,7 @@ sub postprocess_algebra {
     # $string =~s/\\fun/ /g;
 
     # sqrt(3,4) means the 4 root of 3
-    $string =~s/\\sqrt{([^,]+),([^\}]+)}/\\sqrt[$2]{$1}/gs;
+    $string =~s/\\sqrt\{([^,]+),([^\}]+)}/\\sqrt[$2]{$1}/gs;
 
     # log(3,4) means the log base 4 of 3
     $string =~s/\\log\\left\((.+?),(.+?)\\right\)/\\log_{$2}\\left($1\\right)/gs;