Bisection Method

bisecton_method.c

/*
 * metode numerik dengan bisection method
 * author : duken marga
*/

#include <stdio.h>
#include <math.h>
#define EPSILON 10E-10
#define PHI 3.141592654

float f(float x);
int main()
{
	float left, right, mid;
	
	printf("Masukkan nilai pertama : ");
	scanf("%f", &left);
	
	printf("Masukkan nilai kedua : ");
	scanf("%f", &right);
	
	do{
		mid = (right + left) / 2;
		printf("%f %f %f \n", f(left), f(mid), f(right));
		
		if(f(left) * f(mid) < 0){
			right = mid;
		}
		else if(f(right) * f(mid) < 0){
			left = mid;
		}
		else
			break;
		
	}while(abs(right-left) < 2 * EPSILON);
	
	printf("Solusi persamaan adalah : %f", mid);
}

/*
 * f(x)  = x*x - 2*x + 1;
*/
float f(float x){
	return x*x - 9;
}