You may want to review solving
quadratic equations in *x*^{3} first.

If you have *x*^{4} in place
of *x*^{3}, there's yet another twist. As before, we
can only deal with real solutions; but now that means that, if the
Quadratic Formula gives us a negative answer, we throw it out,
since negative numbers don't have real fourth roots. Each positive
number we get from the Quadratic Formula will give us 2 real
fourth roots, one positive ad one negative. (Of course, 0 has just
one fourth root, 0.)