# Turbo C - Finding the equation of a Line Given Two End Points

Here is the Turbo C program for finding the equation of a Line Given Two End Points (x1,y1) and (x2, y2)

The equation for a line is Y = MX + C

Where M = Slope of a Line and C = Intercept

To Find the slope of a line

slope = (y2 - y1) / (x2 - x1)

To Find the intercept of the line, intercept = y1 - (slope) * x1

which would be same as, intercept = y2 - (slope) * x2

## Source Code

#include <stdio.h>

#include <math.h>

void main()

{

float slope, intercept;

float x1, y1, x2, y2;

float dx, dy;

printf("Program to find the equation of a line given two end points\n");

printf("Enter X1: ");

scanf("%f", &x1);

printf("Enter Y1: ");

scanf("%f", &y1);

printf("Enter X2: ");

scanf("%f", &x2);

printf("Enter Y2: ");

scanf("%f", &y2);

dx = x2 - x1;

dy = y2 - y1;

slope = dy / dx;

// y = mx + c

// intercept c = y - mx

intercept = y1 - slope * x1; // which is same as y2 - slope * x2

printf("Equation of the line with end points (%.2f, %.2f) and (%.2f, %.2f) : Y = %.2fX %c %.2f\n", x1, y1, x2, y2, slope, (intercept < 0) ? ' ' : '+',  intercept);

}

## Output

Program to find the equation of a line given two end points

Enter X1: 2

Enter Y1: 3

Enter X2: 5

Enter Y2: 7

Equation of the line with end points (2, 3 and (5, 7) : Y = 1.33333X +0.333333

Press any key to continue . . .