diff --git a/lib/sqlite_extension.rb b/lib/sqlite_extension.rb
index 5e746c0..743475a 100644
--- a/lib/sqlite_extension.rb
+++ b/lib/sqlite_extension.rb
@@ -13,5 +13,28 @@ if ActiveRecord::Base.connection.adapter_name =~ /^sqlite$/i
   database.create_function('pow', 2, :numeric) do |func, base, exponent|
     func.set_result(base.to_f ** exponent.to_f)
   end
+  
+  database.create_function('asin', 1, :numeric) do |func, value|
+    func.set_result(Math.asin(value))
+  end
+  
+  database.create_function('acos', 1, :numeric) do |func, value|
+    func.set_result(Math.acos(value))
+  end
+  
+  database.create_function('radians', 1, :numeric) do |func, value|
+    func.set_result(value.to_f * Math::PI / 180.0)
+  end
+  
+  database.create_function('sqrt', 1, :numeric) do |func, value|
+    func.set_result(Math.sqrt(value))
+  end
 
+#  database.create_function('dist', 5, :numeric) do |func, lat1, long1, lat2, long2, radius|
+#    lat2, long2 = [lat2, long2].map{|l|l * Math::PI/180.0}
+#    func.set_result = radius * Math.acos([1,
+#      Math.cos(lat1.to_f) * Math.cos(long1.to_f) * Math.cos(lat2.to_f) * Math.cos(long2.to_f) + 
+#      Math.cos(lat1.to_f) * Math.sin(long1.to_f) * Math.cos(lat2.to_f) * Math.sin(long2.to_f) + 
+#      Math.sin(lat1.to_f) * Math.sin(lat2.to_f)].min)
+#  end
 end
diff --git a/test/unit/sqlite_extension_test.rb b/test/unit/sqlite_extension_test.rb
index d481331..958067a 100644
--- a/test/unit/sqlite_extension_test.rb
+++ b/test/unit/sqlite_extension_test.rb
@@ -16,4 +16,24 @@ class SQliteExtensionTest < Test::Unit::TestCase
     assert_in_delta 8.0, ActiveRecord::Base.connection.execute('select pow(2.0, 3.0) as result').first['result'], 0.0001
   end
 
+  should 'have arcsine function' do
+    assert_in_delta Math::PI/2, ActiveRecord::Base.connection.execute('select asin(1) as asin').first['asin'], 0.0001
+  end
+  
+  should 'have arccosine function' do
+    assert_in_delta Math::PI, ActiveRecord::Base.connection.execute('select acos(-1.0) as acos').first['acos'], 0.0001
+  end
+
+  should 'have radians function' do
+    assert_in_delta Math::PI/2, ActiveRecord::Base.connection.execute('select radians(90) as rad').first['rad'], 0.0001
+  end
+
+  should 'have square root function' do
+    assert_in_delta 1.4142, ActiveRecord::Base.connection.execute('select sqrt(2) as sqrt').first['sqrt'], 0.0001
+  end
+
+#  should 'have a distance function' do
+#    assert_in_delta 2.28402, ActiveRecord::Base.connection.execute('select dist(32.918593, -96.958444, 32.895155, -96.958444, 3963.19) as dist').first['dist'], 0.0001
+#  end
+
 end
--
libgit2 0.21.2