From 6441620f45006c26f65e73c846609b4c47473685 Mon Sep 17 00:00:00 2001
From: hoangviet1985 <hoang_viet1985@yahoo.com>
Date: Tue, 10 Nov 2015 16:18:07 -0500
Subject: [PATCH] The right signs give the right results

---
 modules/core/src/mathfuncs.cpp | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/modules/core/src/mathfuncs.cpp b/modules/core/src/mathfuncs.cpp
index 4b5327116..9e6b89ff4 100644
--- a/modules/core/src/mathfuncs.cpp
+++ b/modules/core/src/mathfuncs.cpp
@@ -2440,13 +2440,13 @@ int cv::solveCubic( InputArray _coeffs, OutputArray _roots )
         {
             if(R >= 0)
             {
-                x0 = pow(R/4, 1./3) - a1/3;
-                x1 = -pow(2*R, 1./3) - a1/3;
+                x0 = -2*pow(R, 1./3) - a1/3;
+                x1 = pow(R, 1./3) - a1/3;
             }
             else
             {
-                x0 = -pow(-R/4, 1./3) - a1/3;
-                x1 = pow(-2*R, 1./3) - a1/3;
+                x0 = 2*pow(-R, 1./3) - a1/3;
+                x1 = -pow(-R, 1./3) - a1/3;
             }
             x2 = 0;
             n = x0 == x1 ? 1 : 2;