{
"isDocumented" : true,
"arity" : 1,
"name" : "acos",
"qname" : "math:acos",
"signature" : "($arg as xs:double?) as xs:double? external",
"description" : " <div xmlns:xqdoc=\"http://www.xqdoc.org/1.0\"><p xmlns:e=\"http://www.w3.org/1999/XSL/Spec/ElementSyntax\">Returns the arc cosine of the argument, the result being in the range zero to\n +<var>π</var> radians.</p><p xmlns:e=\"http://www.w3.org/1999/XSL/Spec/ElementSyntax\"><example role=\"signature\"><proto name=\"acos\" return-type=\"xs:double?\" isOp=\"no\" prefix=\"math\" returnEmptyOk=\"no\" returnSeq=\"no\" returnVaries=\"no\" isSchema=\"no\" isDatatype=\"no\" isSpecial=\"no\"><arg name=\"arg\" type=\"xs:double?\"/></proto></example></p><p xmlns:e=\"http://www.w3.org/1999/XSL/Spec/ElementSyntax\">This function is <termref def=\"dt-deterministic\">deterministic</termref>, <termref def=\"dt-context-independent\">context-independent</termref>, and <termref def=\"dt-focus-independent\">focus-independent</termref>. </p><p xmlns:e=\"http://www.w3.org/1999/XSL/Spec/ElementSyntax\">If <code>$arg</code> is the empty sequence, the function returns the empty sequence.</p><p xmlns:e=\"http://www.w3.org/1999/XSL/Spec/ElementSyntax\" diff=\"chg\" at=\"G\">Otherwise the result is the arc cosine of <code>$</code><var>θ</var>,\n treated as an angle in radians, as defined in the <bibref ref=\"ieee754-2008\"/>\n specification of the <code>acos</code> function applied to 64-bit binary floating point\n values.</p><p xmlns:e=\"http://www.w3.org/1999/XSL/Spec/ElementSyntax\">The treatment of the <code>invalidOperation</code> exception is defined in <specref ref=\"op.numeric\"/>. </p><p xmlns:e=\"http://www.w3.org/1999/XSL/Spec/ElementSyntax\">If <code>$arg</code> is <code>NaN</code>, or if its absolute value is greater than one,\n then the result is <code>NaN</code>.</p><p xmlns:e=\"http://www.w3.org/1999/XSL/Spec/ElementSyntax\">In other cases the result is an <code>xs:double</code> value representing an angle\n <var>θ</var> in radians in the range <code>0 <= $</code><var>θ</var><code> <=\n +</code><var>π</var>. </p></div>\n",
"summary" : "<p> Returns the arc cosine of the argument, the result being in the range zero to\n + π radians.</p>",
"annotation_str" : "",
"annotations" : [ ],
"updating" : false,
"parameters" : [ {
"name" : "arg",
"type" : "xs:double",
"occurrence" : "?",
"description" : ""
} ],
"returns" : {
"type" : "xs:double?",
"description" : ""
},
"errors" : [ ]
},