Question

Marissa wants to write an abbreviated set of directions for finding coordinates of a figure reflected across the y-axis. Which mapping notation is correct?
1. (x,y) --> (-x,y)
2. (x,y) --> (x,-y) 
3. (x,y) --> (-x,-y) 
4. (x,y) --> (y,x) 

Answer 1

The answer is the very first one! 
(x,y) --> (-x,y) 

It demonstrates a perfect reflection across the y-axis. 

Good Luck! 

Answer 2

Answer:

1. (x,y) --> (-x,y)

Step-by-step explanation:

We are given that,

Marissa needs to write the rule for finding the co-ordinates of a figure reflected across the y-axis.

We know,

Reflection flips the figure over the line of reflection.

So, the reflection of a figure over y-axis will flip the figure over y-axis.

Thus, we get that there will be no change in the y-co-ordinate and the x co-ordinate will be multiplied by a negative sign.

So, the co-ordinates can be found out by the rule,

(x,y)   ----------- >   (-x,y).

Hence, option 1 is correct.