Iteration with one variable using Newtons method.

The program iterates a given functions values of intersection with the x-axis.

The program estimates a given number of intersection values, amongst which the start point of the following iteration can be chosen. These values are found graphically, and after each ended iteration the found intersection value is plotted with a cross together with the iterated function. This way it is easy to determine if the found intersection value is the wished intersection value.