Question

point d is the image of d(-2,1) under a reflection across the x - axis. what are the coordinates of d? ( )

Explanation:

Step1: Recall reflection rule

When a point $(x,y)$ is reflected across the $x -$axis, the rule is $(x,y)\to(x, - y)$.

Step2: Apply rule to point D

For point $D(-2,1)$, using the rule, $x=-2$ and $y = 1$. After reflection, the $x$-coordinate remains the same and the $y$-coordinate changes sign. So the new $y$-coordinate is $-1$.

Answer:

$(-2,-1)$