Download presentation

Presentation is loading. Please wait.

Published byGalilea Maltman Modified over 4 years ago

1
www.le.ac.uk Numerical Methods: Finding Roots Department of Mathematics University of Leicester

2
Content MotivationChange of sign methodIterative methodNewton-Raphson method

3
Reasons for Finding Roots by Numerical Methods If the data is obtained from observations, it often won’t have an equation which accurately models Some equations are not easy to solve Can program a computer to solve equations for us Next Iterative method Newton- Raphson Change of sign method Motivation

4
Solving equations by change of sign This is also known as ‘Iteration by Bisection’ It is done by bisecting an interval we know the solution lies in repeatedly Next Iterative method Newton- Raphson Change of sign method Motivation

5
METHOD Find an interval in which the solution lies Split the interval into 2 equal parts Find the change of sign Repeat Solving equations by change of sign Next Iterative method Newton- Raphson Change of sign method Motivation

6
Solving equations by change of sign Next Iterative method Newton- Raphson Change of sign method Motivation

7
Solving equations by change of sign Next Iterative method Newton- Raphson Change of sign method Motivation

8
Solving equations by change of sign Next Iterative method Newton- Raphson Change of sign method Motivation

9
Step 3: Now we just keep repeating the process Solving equations by change of sign Next Iterative method Newton- Raphson Change of sign method Motivation

10
Solving equations by change of sign Next Iterative method Newton- Raphson Change of sign method Motivation

11
So to 3 s.f. the solution is Solving equations by change of sign Next Iterative method Newton- Raphson Change of sign method Motivation

12
Solving equations by change of sign Next Iterative method Newton- Raphson Change of sign method Motivation

13
Solving using iterative method ‘Iteration’ is the process of repeatedly using a previous result to obtain a new result Next Iterative method Newton- Raphson Change of sign method Motivation

14
Solving using iterative method Next Iterative method Newton- Raphson Change of sign method Motivation

15
Solving using iterative method Next Iterative method Newton- Raphson Change of sign method Motivation

16
Solving using iterative method Next Iterative method Newton- Raphson Change of sign method Motivation

17
Solving using iterative method Next Iterative method Newton- Raphson Change of sign method Motivation

18
Solving using iterative method Next Iterative method Newton- Raphson Change of sign method Motivation

19
Click on a seed value to see the cobweb: start here start here start here start here start here start here Clear Cobwebs Next Iterative method Newton- Raphson Change of sign method Motivation

20
Solving using iterative method Next Iterative method Newton- Raphson Change of sign method Motivation

21
Solving using iterative method Next Iterative method Newton- Raphson Change of sign method Motivation

22
This gives us the solution to 3 d.p. Solving using iterative method Next Iterative method Newton- Raphson Change of sign method Motivation

23
Solving using iterative method Next Iterative method Newton- Raphson Change of sign method Motivation

24
Newton-Raphson Method Sometimes known as the Newton Method Named after Issac Newton and Joseph Raphson Iteratively finds successively better approximations to the roots Next Iterative method Newton- Raphson Change of sign method Motivation

25
Newton-Raphson Method Next Iterative method Newton- Raphson Change of sign method Motivation

26
Newton-Raphson Method Next Iterative method Newton- Raphson Change of sign method Motivation

27
Newton-Raphson Method Next Iterative method Newton- Raphson Change of sign method Motivation

28
Newton-Raphson Method Next Iterative method Newton- Raphson Change of sign method Motivation

29
Newton-Raphson Method So this means that the cube root of 37 is approximately 3.3322 Next Iterative method Newton- Raphson Change of sign method Motivation

Similar presentations

OK

Lecture 6 Numerical Analysis. Solution of Non-Linear Equations Chapter 2.

Lecture 6 Numerical Analysis. Solution of Non-Linear Equations Chapter 2.

© 2018 SlidePlayer.com Inc.

All rights reserved.

To make this website work, we log user data and share it with processors. To use this website, you must agree to our Privacy Policy, including cookie policy.

Ads by Google