Quadratic Equations and their roots.

Question

I want to know if there is any way of finding out whether a quadratic equation has ratonal roots or not.

Answer 1

Using the quadratic formula, $x = \frac{-b\pm\sqrt{b^2-4ac}}{2a}$. This means that you have to check $b^2-4ac$ whether it is a square number to check if the roots are under the square root.