Question

a△ is reflected across the y - axis in picture a/1. write the rule for the reflection (x,y)=( )

Explanation:

Step1: Recall reflection rule

When a point $(x,y)$ is reflected across the y - axis, the x - coordinate changes sign and the y - coordinate remains the same.

Step2: Write the rule

The rule for reflection across the y - axis is $(x,y)\to(-x,y)$.

Answer:

$(x,y)\to(-x,y)$