Answer 2A

The Mandelbrot Set Explorer

Answer 2A: The only orbit that does not lie in the filled Julia set of x2 - 1 is the orbit of seed D, which escapes to infinity.

In analogy with our coloring scheme for the Mandelbrot set, colored points are points whose orbit tends to infinity (with the color telling us how quickly the orbit escapes). Black points have orbits that do not escape, and so the black points form the filled Julia set.