From previous discussions, we know that an equation of the form
has two roots, but the roots are not always distinct. Take, for example, the equation

We can see that x = –2 when y = 0. This
occurs twice, so we call it a double root. It is a single distinct result,
but still considered as two roots.
What happens when the equation will not factor over the set of real numbers?
Consider
| (1) |