Bisection Method : The bisection 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 bisection method is also known as interval halving method, root-finding method, binary search method or dichotomy method.
Algorithm :
For any continuous function f(x),

• Find two points, say a and b such that a < b and f(a)* f(b) < 0 and initialize error e (depends upto what accuracy you want the result)
• Find the midpoint of a and b, say “m”
• m is the root of the given function if f(m) = 0; else follow the next step
• Divide the interval [a, b]
• If f(a)*f(m) > 0 then a = m
else b = m
• Repeat above steps until |f(m)| < e.