Roots and Quadratic Coefficients of Polynomials
Use of the MODIFY tool means you can explore the effect on the graph of altering the coefficients of a quadratic expression. It is advisable to start with the coefficient of the x^2 as 1.
You can use the G-SOLVE tool to find roots.
The fx-CG20 is ideal to quickly explore and check any hypothesis you have to connect the coordinate coefficients and the roots of the curve.