nag_quartic_roots (c02alc) Example Program Results

 Roots of quartic equation          Error estimates
                                   (machine-dependent)

 z =    2.00000    0.00000*i        3.39305e-15
 z =   -2.00000    0.00000*i        5.29913e-15
 z =   -1.00000    3.00000*i        4.54822e-15
 z =   -1.00000   -3.00000*i        4.54822e-15