This draws quadratics in real time, the red dot represents the y-intercept, the green dots are the roots of the equation, and a, b and c are just parameters of the curve. A is the "curviness", B the "gradient", C is the intercept. all of these are toggleable sliders and the curve updates in real time. There is also an option of 3 animations (based on sin and cos functions that I don't understand) and static. The roots are plotted using the quadratic formula and when there are no roots to plot, it uses complex numbers instead: when there are roots their y coordinate is 0 and the x coordinate is worked out using the quadratic formula, but when there are no real roots, the value under the square root in the formula is negative, and the square root of a negative number is a complex number, in this scenario the y axis is used to plot the complex numbers, so the x axis is the real part of the complex number, and the y axis is used to plot the imaginary part of the complex numbers, so when there are no real roots the graph is representing the complex plane/domain.
