Question

State the co-ordinates of the images of the following points under reflection in the $y$-axis:

(i) $(2,8)$

Answer 1

Given point: $(2,8)$

Reflection in the $y$-axis, $M_y(x,y)=(-x,y)$

$\Rightarrow M_y(2,8)=(-2,8)$

$\therefore$The co-ordinates of the image of the given point under reflection in the $y$-axis are $(-2,8)$.