The roots are
-0.500000000000000 - 1.038260698286168 i
-0.500000000000000 + 1.038260698286168 i
-0.500000000000000 - 0.398736694441202 i
-0.500000000000000 + 0.398736694441202 i
-0.500000000000000 - 0.114121737195075 i
-0.500000000000000 + 0.114121737195075 i
