Question

If the image of the point $(2,1)$ with respect to a line mirror be $(5,2)$, find the equation of the mirror.

Answer 1

We have

$y-\frac{3}{2}=-3(x-\frac{7}{2})$

$2y-3=-3(2x-7)$

$2y-3=-6x+21$

$6x+2y=24$

$3x+y=12$

Hence this is the centre