Updated history and extended docs

HISTORY.md

@@ -1,6 +1,12 @@
 # History
 
 
+## not yet released, version 2.7.1
+
+- Extended function `pow` to return the real root for cubic roots of negative
+  numbers. See #525, #482, #567.
+
+
 ## 2016-02-03, version 2.7.0
 
 - Added more unit aliases for time: `secs`, `mins`, `hr`, `hrs`. See #551.

lib/function/arithmetic/pow.js

@@ -21,6 +21,7 @@ function factory (type, config, load, typed) {
    * For cubic roots of negative numbers, the function returns the principal
    * root by default. In order to let the function return the real root,
    * math.js can be configured with `math.config({predictable: true})`.
+   * To retrieve all cubic roots of a value, use `math.cbrt(x, true)`.
    *
    * Syntax:
    *
@@ -38,7 +39,7 @@ function factory (type, config, load, typed) {
    *
    * See also:
    *
-   *    multiply, sqrt
+   *    multiply, sqrt, cbrt, nthRoot
    *
    * @param  {number | BigNumber | Complex | Array | Matrix} x  The base
    * @param  {number | BigNumber | Complex} y                   The exponent