Numerical Analysis/Bisection Method Worked Example

From Wikiversity
Jump to navigation Jump to search

X^3=20 ,f(X), X4=4, X1=1 take four iterations .


[edit | edit source]

Find an approximation of correct to within 10-4 by using the bisection method on . starting on [1, 2].

Analysis of the Problem

[edit | edit source]

The number of iterations we will use, n, must satisfy the following formula:
Thus, we will use 14 iterations of the bisection method.

Iteration #1

[edit | edit source]

First, we find the midpoint of the interval [1, 2]:

Then we check if is positive or negative:

The value of is negative, which means that is less than .

We therefore use as the left endpoint of our new interval and keep 2 as the right endpoint.


Iteration #2

[edit | edit source]

Repeat the process from Iteration #1 to do Iteration #2:

Iteration #3 - Iteration #14

[edit | edit source]

Complete Iteration #3 - Iteration #14:

the final answer is follow or describe below


[edit | edit source]

Thus, we have found that

is an approximation of correct to within 10-4.