/*****************************************************************************
*       Calculates the slope, midpoint, length and equation of the line      *
*       connecting two coordinates on the cartesian plane.                   * 
*       Inputed: x1, y1 (coor. of first point), x2, y2 (coor of sec point)   *
*       Outputed: slope, midpoint, length, equation [see below]              *
*       Written: September 21, 2001                                          *
*       By: Ronald Roberts                                                   *
*****************************************************************************/

//Program 8
//21SEP01
#include <iostream.h>
#include <math.h>
int main()
{
/* declaration of variables */ 
double x1=0, x2=0, y1=0, y2=0, slope=0, mid1=0, mid2=0, length=0, b=0;

/* instructions and user input */
cout<<"This program computes slope, midpoint, and length"<<endl;
cout<<"The equation of a line equals y=mx+b where m=slope and b=y-intercept"<<endl;
cout<<"Please enter the first point(x,y):"<<endl;
cin>>x1>>y1;
cout<<"Please enter the second point(x,y):"<<endl;
cin>>x2>>y2;

/* calculation code */ 
slope=(y2-y1)/(x2-x1);
mid1=(x2+x1)/2;
mid2=(y2-y1)/2;
length=sqrt(pow((x2-x1), 2)+pow((y2-y1), 2));
b=y1-slope*x1;

/* output results */ 
cout<<"The slope is "<<slope<<" ."<<endl;
cout<<"The midpoint is ("<<mid1<<", "<<mid2<<")."<<endl;
cout<<"The length is "<<length<<" ."<<endl;
cout<<"The equation is y="<<slope<<"x+"<<b<<" ."<<endl;

return 0;
}

/* OUTPUT
This program computes slope, midpoint, and length
The equation of a line equals y=mx+b where m=slope and b=y-intercept
Please enter the first point(x,y):
2
3
Please enter the second point(x,y):
4
5
The slope is 1 .
The midpoint is (3, 1).
The length is 2.828427 .
The equation is y=1x+1 .
*/