An introduction to C++, is very beneficial to the research group. I have written these

tutorials so programming resources are available. In this section I will write a little more about programming and give an example that will enable you to work, and learn c++ programming. In any programming language we always get an structure to how the program is build onto. One example of this is how we by in building a source code, what does it take to have a program. Here is program structure that shows how a program works.

The problem that we have is the following.

You want to find the roots of a quadratic equation, given that, the standard equation for a quadratic equation is

Ax^2+Bx+C=0.

We we want to start design a program that would find the solutions to the quadratic equations, because what we want to do is find a good solution based on our knowledge of quadratic equations.

Here is brief of how to configurate your Unix or Linux machine, depeninng from what you are working from.

I am particular working from the webster server.

If you are at teminal, make a directory that you can save all your work on: type

>mkdir practice

>cd practice

> emacs -nw quadratic_roots.cpp

My screen shot looks like this.

Type the following code in this file:

//******************************************************************

//Quadratic Root Finder: This program finds the roots of any

//quadratic equation. Using the equation x=-b+or-sqrt(b^2-4*a*c)/2*a

//******************************************************************

//Header Files

#include<iostream>

#include<cmath>

using namespace std;

int main()

{

//declare variables

int a=0, b=0, c=0;

double discriminant=0, x_1=0, x_2=0;

cout<<"Enter a, b, and c.";

cin>>a>>b>>c;

//Calculations

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

if (discriminant > 0)

x_1=((-b)+sqrt(discriminant))/(2*a);

x_2=((-b)-sqrt(discriminant))/(2*a);

cout<<"The two real roots are "<<x_1<<" and "<<x_2<<" ."<<endl;

if (discriminant < 0)

cout<<"The roots are complex."<<endl;

else if (discriminant == 0)

x_1=(-b)/(2*a);

cout<<"The only root is "<<x_1<<endl;

return 0;

}

*Note you can also copy and paste it in your file. To compile this file what we need to do is the following: In the prompth. Type the following comand.

>g++ quadratic_roots.cpp -o quadratic_roots.exe

What this command does is compiles the file quadratic_roots.cpp and turns that in an exacutable file. To execute the file, type what is shown below:

>./quadratic_roots.exe

It should run just fine. Even though we might find some problems trying to understand what it is doing.

Things you have learn:

1. Edit a new c++ file

2. Compile a c++ file and execute it.