Newton-Raphson Method to Find Roots of a Polynomial

Newton's method can be used to find roots or zero crossing of a real valued function.

Root finding problems are often encountered in numerical analysis. Newton-Raphson method is the simplest among all root finding algorithm, which is illustrated to find roots of a simple polynomial X*X-7=0.
Ref [1]: http://www.math.colostate.edu/~gerhard/classes/331/lab/newton.html

Ref [2]:
http://en.wikipedia.org/wiki/Newton's_method