Question 1182539
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Refer to this handy chart
<img width="35%" src = "https://www.onlinemath4all.com/images/rotation1.png">
(image source: <a href = "https://www.onlinemath4all.com/rotation-transformation.html">OnlineMath4all.com</a>)


The chart tells us that P(8,1) rotates to Q(-1,8)
We use the rule in the second row telling us (x,y) rotates to (-y,x) when doing a 90 degree counter-clockwise rotation.
We swap the x and y coordinates, then make the first coordinate (after the swap) the opposite sign of what it was before.


Now, we apply a reflection over the line y = x
The rule is that any (x,y) point reflects to (y,x). The x and y coordinates swap. There are no sign changes here.
Q(-1,8) reflects to R(8,-1)


When applying a y axis reflection, we change the sign on the x coordinate but the y coordinate stays the same. 
In general, we go from (x,y) to (-x,y)
Specifically, R(8,-1) reflects to S(-8,-1)


<font color=red>Answer: (-8,-1)</font>


Diagram:
<img width="50%" src = "https://i.imgur.com/BTIfgzi.png">
I used GeoGebra to make the diagram.
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