non real roots come in pairs. so an example of a non real root would be y=ax + bi and y = ax - bi.
the fact that it is rational with a multiplicity of 2 means that their is a root that is raised to the power of 2. So we now have y = (x +a)^2 or something like it.
The leading coefficient is even. That means y = 2c * (x + 2)^2 (ax + bi)(ax - bi)
The fact that the two variables (x and y) both go to minus infinity means that c<0. c is minus).
