Find the other end point of a line with given one end and mid

Given a midpoint of line(m1, m2) and one coordinate of a line (x1, y1), find the other end point(x2, y2) of a line

Examples:

Input  : x1 = –1, y1 = 2, and 
         m1 = 3, m2 = –6
Output : x2 = 7, y2 = 10

Input  : x1 = 6.4, y1 = 3 and 
         m1 = –10.7, m2 = 4
Output : x2 = 3, y2 = 4


The Midpoint Formula: The midpoint of two points, (x1, y2) and (x2, y2) is the point M found by using:
M=((x1+x2)/2, (y1+y2)/2),
We have need of a (x2, y2) so we modifies the formula

          m1 = ((x1+x2)/2),  m2 = ((y1+y2)/2)
          2*m1 = (x1+x2),  2*m2 = (y1+y2)
          x2 = (2*m1 - x1),  y2 = (2*m2 - y1)

C++


[sourcecode language=”CPP”]
// CPP program to find the end point of a line
#include <iostream>
using namespace std;

// CPP function to find the end point of a line
void otherEndPoint(int x1, int y1, int m1, int m2)
{
// find end point for x cordinates
float x2 = (float)(2 * m1 – x1);

// find end point for y cordinates
float y2 = (float)(2 * m2 – y1);

cout << "x2 = " << x2 << ", "
<< "y2 = " << y2;
}

// Driven Program
int main()
{
int x1 = -4, y1 = -1, m1 = 3, m2 = 5;
otherEndPoint(x1, y1, m1, m2);
return 0;
}
[/sourcecode]

Java


[sourcecode language=”Java”]
// Java program to find the end point of a line
class GFG {

// CPP function to find the end point
// of a line
static void otherEndPoint(int x1, int y1,
int m1, int m2)
{
// find end point for x cordinates
float x2 = (float)(2 * m1 – x1);

// find end point for y cordinates
float y2 = (float)(2 * m2 – y1);

System.out.println("x2 = " + x2 + ", "
+ "y2 = " + y2);
}

// Driven Program
public static void main(String args[])
{
int x1 = -4, y1 = -1, m1 = 3, m2 = 5;
otherEndPoint(x1, y1, m1, m2);
}
}

// This code is contributed by JaideepPyne.
[/sourcecode]

C#


[sourcecode language=”CSHARP” highlight=”7-21″]
// C# program to find the
// end point of a line
using System;

class GFG {

// function to find the
// end pointof a line
static void otherEndPoint(int x1, int y1,
int m1, int m2)
{

// find end point for x cordinates
float x2 = (float)(2 * m1 – x1);

// find end point for y cordinates
float y2 = (float)(2 * m2 – y1);

Console.WriteLine("x2 = " + x2 + ", "
+ "y2 = " + y2);
}

// Driver Program
public static void Main(String []args)
{
int x1 = -4, y1 = -1, m1 = 3, m2 = 5;
otherEndPoint(x1, y1, m1, m2);
}
}

// This code is contributed by nitin mittal.

[/sourcecode]

PHP


[sourcecode language=”php”]
<?php
// php program to find the end point of a line

// PHP function to find the end point of a line
function otherEndPoint($x1, $y1, $m1, $m2)
{

// find end point for x cordinates
$x2 = (2 * $m1 – $x1);

// find end point for y cordinates
$y2 = (2 * $m2 – $y1);

echo "x2 = " . $x2 . ", y2 = " . $y2 ;
}

// Driven Program
$x1 = -4; $y1 = -1; $m1 = 3; $m2 = 5;
otherEndPoint($x1, $y1, $m1, $m2);

// This code is contributed by nitin mittal.
?>
[/sourcecode]

Output:

x2 = 10, y2 = 11


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