Move n, a, and b to see how they move the parabola and the line. Move D_1 to move point D to see the locus of all possible values of C1 and C2 outline the cartesian parabola.
The constant, 1/n is leading coefficient of function y. Point E is a units away from point D on the y-axis. Point A is a point on the x-axis. Line f goes through the points A and E. Line f crosses parabola y at two points, C1 and C2. The purple dashed line is the locus of all possible values of C1 and C2. We can see it outlines the cartesian parabola.