Question

Find the co-ordinate of the points which divide externally the line joining (1,-3) and (-3,9) in the ratio 1 : 3.

Answer 1

Let A be $(1,-3)$

and B be $(-3,9)$

Let coordinate of point P be $(x,y)$ that divides the line joining A&B in the ratio $1:3$ externally.

We know that,

Coordinate of point P dividing line joining A and B in ratio m:n is given by:-

$x=\frac{m{x}_2-n{x}_1}{m-n}$

and similarly y is obtained.

On applying formula:-

$x=\frac{1\times (-3)-1\times 1}{1-3}$

$x=2$

And similarly,

$y=-9$

Thus, $P=(2,-9)$