# What are the coordinates of point A (4,-1) after it has been reflected over the y-axis?

Jun 5, 2018

$\left(4 , - 1\right)$ after reflection over the y-axis would become color(red)(""(-4,-1))

#### Explanation:

A reflection over the y-axis leaves the point the same distance above the x-axis (that is the y-coordinate value does not change).

The x-coordinate value becomes an equal distance from the y-axis but on the other side of the y-axis (that is the x-coordinate value becomes the negative of what it was).

Jul 28, 2018

color(purple)(A ((4),(1)) to A'((-4), (-1))

#### Explanation:

As can be seen from the above figure,

Mapping formula for reflection over y-axis is

$\left(\begin{matrix}x \\ y\end{matrix}\right) \to \left(\begin{matrix}- x \\ y\end{matrix}\right)$

:. color(purple)(A ((4),(-1)) to A'((-4), (-1))