How to approximately draw a parabola given its equation : ax^2 + bx + c = y

First check if the roots of y are real or not from Discriminant :
If D > 0, the parabola cuts the x-axis at two points
If D=0, the parabola touches the x-axis
If D<0, the parabola doesnt touches or cuts the x-axis
Check the sum of roots and product of roots from formula -b/a and c/a.
Check if roots are positive or negative. Hence, draw the parabola according to the roots
Thanks
Bharat Bajaj
IIT Delhi