1diff --git a/src/RawFormulas.ts b/src/RawFormulas.ts
 2index f9a645b..9c81885 100644
 3--- a/src/RawFormulas.ts
 4+++ b/src/RawFormulas.ts
 5@@ -43,6 +43,12 @@ function valueToNumber(value: any) : number {
 6   return 0;
 7 }
 8 
 9+/**
10+ * Returns the absolute value of a number.
11+ * @param value to get the absolute value of.
12+ * @returns {number} absolute value
13+ * @constructor
14+ */
15 var ABS = function (value?) {
16   checkArgumentsLength(arguments, 1);
17   value = valueToNumber(value);
18@@ -106,6 +112,12 @@ var ACCRINT = function (issue, first, settlement, rate, par, frequency, basis) {
19   return par * rate * factor;
20 };
21 
22+/**
23+ * Returns the inverse cosine of a value, in radians.
24+ * @param value The value for which to calculate the inverse cosine. Must be between -1 and 1, inclusive.
25+ * @returns {number} inverse cosine of value
26+ * @constructor
27+ */
28 var ACOS = function (value?) {
29   checkArgumentsLength(arguments, 1);
30   value = valueToNumber(value);
31@@ -117,6 +129,12 @@ var ACOS = function (value?) {
32   return Math.acos(value);
33 };
34 
35+/**
36+ * Returns the inverse hyperbolic cosine of a number.
37+ * @param value The value for which to calculate the inverse hyperbolic cosine. Must be greater than or equal to 1.
38+ * @returns {number} to find the inverse hyperbolic cosine for.
39+ * @constructor
40+ */
41 var ACOSH = function (value?) {
42   checkArgumentsLength(arguments, 1);
43   value = valueToNumber(value);
44@@ -125,6 +143,7 @@ var ACOSH = function (value?) {
45   }
46   return Math.log(value + Math.sqrt(value * value - 1));
47 };
48+
49 var ACOTH = Formula["ACOTH"];
50 var AND = Formula["AND"];
51 var ARABIC = Formula["ARABIC"];