diff --git a/tests/LinearAlgebra/Eigen/EigenvalueTest.php b/tests/LinearAlgebra/Eigen/EigenvalueTest.php
index 0b1fc95a9..af47150dd 100644
--- a/tests/LinearAlgebra/Eigen/EigenvalueTest.php
+++ b/tests/LinearAlgebra/Eigen/EigenvalueTest.php
@@ -220,6 +220,24 @@ public function dataProviderForEigenvalues(): array
                 [2, 2, 1],
                 2,
             ],
+            [
+                [
+                    [2, 0, 1],
+                    [2, 1, 2],
+                    [3, 0, 4]
+                ],
+                [5, 1, 1],
+                5,
+            ],
+            [ // Matrix has duplicate eigenvalues. no solution on the axis
+                [
+                    [2, 2, -3],
+                    [2, 5, -6],
+                    [3, 6, -8],
+                ],
+                [-3, 1, 1],
+                -3
+            ],
             [
                 [
                     [1, 2, 1],
@@ -276,6 +294,18 @@ public function dataProviderForLargeMatrixEigenvalues(): array
                 ],
                 [4, 3, 2, -2, 1, -1],
                 4,
+            ], 
+            [ // Failing case
+                [
+                    [2,0,0,0,0,0],
+                    [0,2,0,0,0,1729.7],
+                    [0,0,2,0,-1729.7,0],
+                    [0,0,0,0,0,0],
+                    [0,0,-1729.7,0,2.82879*10**6,0],
+                    [0,1729.7,0,0,0,2.82879*10**6]
+                ],
+                [2828791.05765, 0.94235235527, 0.94235235527, 2828791.05765, 2, 0],
+                2828791.05765
             ]
         ];
     }