Add a comment to a Math.qubicnewton

diff --git a/org/w3c/dom/smil.js b/org/w3c/dom/smil.js
index bdff79d..5d04e91 100644 (file)
--- a/org/w3c/dom/smil.js
+++ b/org/w3c/dom/smil.js
@@ -637,6 +637,7 @@ Math.qubicnewton = function(a0, a1, a2, a3, b) {
       fb = eps = void 0;\r
       return b;\r
     } else {\r
+      /*分母は与えられた三次方程式を微分したもの*/\r
       b =  b - fb / (3* a0 *b*b + 2 * a1 *b + a2);\r
       fb = a0 *b*b*b + a1 *b*b + a2*b + a3;\r
     }\r