I'm not sure if you would be required to justify it mathematically it, or if you could explain it in writing. But essentially, x^4 will always be positive, Ax^2 will always be positive (as A is strictly positive) and B must be positive. Thus, adding 3 positive numbers cannot result in a root for the equation.

I'm not sure if you would be required to justify it mathematically it, or if you could explain it in writing. But essentially, x^4 will always be positive, Ax^2 will always be positive (as A is strictly positive) and B must be positive. Thus, adding 3 positive numbers cannot result in a root for the equation.