Trapezoidal Difference Method : The Trapezoidal Difference Method is used to find the roots of a polynomial equation. It separates the interval and subdivides the interval in which the root of the equation lies. The principle behind this method is the intermediate theorem for continuous functions. It works by narrowing the gap between the positive and negative intervals until it closes in on the correct answer. The Trapezoidal Difference Method is also known as interval halving method, root-finding method, binary search method or dichotomy method.