Roots of the polynomial x^4-(1+2i)*x^2+2i Unpolished roots: root # real imag. 1 -1.000000 -1.000000 2 -1.000000 0.000000 3 1.000000 1.000000 4 1.000000 0.000000 Corrupted roots: root # real imag. 1 -1.010000 -1.010000 2 -1.020000 0.000000 3 1.030000 1.030000 4 1.040000 0.000000 Polished roots: root # real imag. 1 -1.000000 -1.000000 2 -1.000000 0.000000 3 1.000000 1.000000 4 1.000000 0.000000