Introduction To C++ Programming - Part 6.

C++ Program To Calculate Standard Deviation Of Given Numbers

#include <iostream>

#include <cmath>

using namespace std;

int main() {

int n , j ,y;

double _sum=0 , variance;

cout << "How Many Numbers To Type? ";

cin >> y;

cout << endl;

double max[y];

for(n=0;n<=y-1;n++) {

cout << "Enter Number " << n+1 << " : ";

cin >> max[n];

}

n=0;

cout << endl;

cout << "\nSo The Numbers Are:\t";

for(j=0;j<=y-1;j++) {

cout << max[n] << "\t";

_sum+=max[n];

n++;

}


double mean = _sum/n;

cout << endl << "\nSum: "<< _sum << endl;

cout << "Mean: " << mean << endl;

n=0; j=0; _sum=0;

for(j=0;j<=y-1;j++) {

max[n]=pow((max[n]-mean),2);

_sum+=max[n];

n++;

}

variance=_sum/(n-1);

cout << "Variance: " << variance << endl;

cout << "Standard Deviation: " << sqrt(variance) << "\n\n";

}

C++ Program To Find The Roots Of A Quadratic Equation

#include <iostream>

#include <cmath>

using namespace std;

int main() {

float a, b, c, x1, x2, determinant, realPart, imaginaryPart;

cout << "Enter The Coefficients (a, b, c): " << endl;

cin >> a >> b >> c;

while (!a) {

cout << "The Value Of a Cannot Be Zero." << endl;

cout << "\nEnter The Coefficients (a, b, c): " << endl;

cin >> a >> b >> c;

}

determinant = b*b - 4*a*c;

if (determinant > 0) {

x1 = (-b + sqrt(determinant)) / (2*a);

x2 = (-b - sqrt(determinant)) / (2*a);

cout << "\nRoots Are Real And Different." << endl;

cout << "x1 = " << x1 << endl;

cout << "x2 = " << x2 << endl;

}

else if (determinant == 0) {

cout << "\nRoots Are Real And Same." << endl;

x1 = (-b + sqrt(determinant)) / (2*a);

cout << "x1 = x2 =" << x1 << endl;

}

else {

realPart = -b/(2*a);

imaginaryPart =sqrt(-determinant)/(2*a);

cout << "\nRoots Are Complex And Different."  << endl;

cout << "x1 = " << realPart << "+" << imaginaryPart << "i" << endl;

cout << "x2 = " << realPart << "-" << imaginaryPart << "i" << endl;

}

return 0;

}