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6 votes
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Rachel is using a coordinate plane to reflect points over the y-axis she claims that (x,y) =(x,y) represents a reflection over the y axis since the point (0,4) is mapped to the image point (O,4) and the (0,-2) is mapped to the image point (0,-2).

Rachel is using a coordinate plane to reflect points over the y-axis she claims that-example-1
User Kingamajick
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1 Answer

20 votes
20 votes

Rachel is wrong, because she is claiming that


(x,y)\rightarrow(x,y)

Is a reflection over the y-axis. because


\begin{gathered} (0,4)\rightarrow(0,4) \\ (0,-2)\rightarrow(0,-2) \end{gathered}

A reflection over the y-axis is actually represented as:


(x,y)\rightarrow(-x,y)

But because both of the points that Rachel chose have an x coordinate of 0, and -0 = 0 , Rachel thought that her reasoning was right, when it wasn't.

In fact, every point that is in the y-axis (x coordinate = 0) its mapped to itself when reflected over the y axis.

This way, the correct answer is:

C. Rachel's claims is incorrect since her examples are both in the y-axis

User Dimitri T
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