Julia Sets and the Mandelbrot Set

Real Newton's Method

Derivation of the Newton's Method Formula

We derive the relation between x1 and x0; the others are similar.
Note the points (x0, f(x0)) and (x1, 0) lie on the line tangent to the graph of y = f(x) at the point (x0, f(x0)).
The slope of the tangent line is f '(x0), so we have
f '(x0) = (f(x0) - 0) / (x0 - x1)
Solving this for x1 gives
x1 = x0 - f(x0)/f '(x0)

Return to real Newton's Method