Added Bisection method in CPP

cpp/bisection.cpp

@@ -0,0 +1,58 @@
+#include<bits/stdc++.h>
+using namespace std;
+
+#define EPSILON 0.01
+#define MOD 1000
+
+int MAX_POWER;
+double coef_arr[MAX_POWER+1];
+
+double get_val(double x){
+	double val = 0;
+	for(int i=0; i<=MAX_POWER; i++){
+		val += coef_arr[i]*pow(x, i);
+	}
+	return val;
+}
+
+double get_roots_by_bisection(double a, double b){
+	double c;
+	if(get_val(b)<0){
+		c=b;
+		b=a;
+		a=c;
+	}
+	while (abs(b-a) >= EPSILON){
+		c = (a+b)/2;
+
+		if (get_val(c) == 0.0)
+			break;
+
+		else if (get_val(c)*get_val(a) < 0)
+			b = c;
+
+		else
+			a = c;
+	}
+	return c;
+}
+
+int main(){
+	srand(time(0));
+	double a, b, ans; 
+
+  cout << "Enter highest power in polynomial";
+  cin >> MAX_POWER;
+
+  cout << "Enter co-effecients of polynomial starting from degree 0 to " << MAX_POWER;
+	for(int i=0; i<=MAX_POWER; i++){
+		cin >> coef_arr[i];
+	}
+
+	a = -rand()%MOD;
+	b = rand()%MOD;
+	ans = get_roots_by_bisection(a, b);
+
+	cout << " The value of root is : " << ans;
+	return 0;
+}

cpp/newton_rhapson.cpp

@@ -0,0 +1,41 @@
+//Newton-Raphson Method
+#include<iostream>
+#include<cmath>
+#include<iomanip>
+using namespace std;
+double f(double x);    //declare the function for the given equation
+double f(double x)    //define the function here, ie give the equation
+{
+    double a=pow(x,3.0)-x-11.0;    //write the equation whose roots are to be determined
+    return a;
+}
+double fprime(double x);
+double fprime(double x)
+{
+    double b=3*pow(x,2.0)-1.0;        //write the first derivative of the equation
+    return b;
+}
+int main()
+{
+    double x,x1,e,fx,fx1;
+    cout.precision(4);        //set the precision
+    cout.setf(ios::fixed);    
+    cout<<"Enter the initial guess\n";    //take an intial guess
+    cin>>x1;
+    cout<<"Enter desired accuracy\n";    //take the desired accuracy
+    cin>>e;
+    fx=f(x);                
+    fx1=fprime(x);
+    cout <<"x{i}"<<"    "<<"x{i+1}"<<"        "<<"|x{i+1}-x{i}|"<<endl;                
+
+    do            
+    {
+        x=x1;                /*make x equal to the last calculated value of                             x1*/
+        fx=f(x);            //simplifying f(x)to fx
+        fx1=fprime(x);            //simplifying fprime(x) to fx1
+        x1=x-(fx/fx1);            /*calculate x{1} from x, fx and fx1*/ 
+        cout<<x<<"     "<<x1<<"           "<<abs(x1-x)<<endl;        
+    }while (fabs(x1-x)>=e);            /*if |x{i+1}-x{i}| remains greater than the desired accuracy, continue the loop*/
+    cout<<"The root of the equation is "<<x1<<endl;
+    return 0;
+}