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Fixed Point Iteration Atom Feed 0

In Brief Find zeros of a function near a given point.
# 's
 1/*
2 By David Isaacson, 2003
3 Released into the Public Domain
4
5 fixedpt.c
6
7 The puropse of this program is to find the zero near x=1 of
8 f(x)=2x^3+4x^2-2x-5=0
9
10this can be rearranged into x=g(x)=(-1/13)(2x^3+4x^2-15x-5)
11 */
12
13#include <stdio.h>
14#include <math.h>
15
16int main()
17{
18 float x; //the start coord
19 float xnew; //the end coord
20
21 printf("Hello\n");
22
23 printf("What value shall we start at? ");
24 scanf("%f",&xnew);
25
26 do
27 {
28 x=xnew;
29 xnew=(2*x*x*x+4*x*x-15*x-5)/-13;//x=g(x)
30 }while(x!=xnew); //again going to the max of the software
31
32 printf("The graphs intersect at %.3f \n",xnew);
33 //this prints xnew to a precision of 3 decimal places
34
35 return 0;
36}
37
38/*
39 When I ran this on my computer, I recieved the result:
40
41 Hello
42 What value shall we start at? 1
43 The graphs intersect at 1.078
44
45 */

Find zeros of a function near a given point.