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40 votes
Find the image C (-1,3) under the transformations T (-2,3) ° r x-axis

User Ranieribt
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1 Answer

16 votes
16 votes

First, we have that the equation to calculate the reflection over the x-axis is:


r_x(x,y)=(x,-y)

And the forumal for the reflection of point 'a' across the point 'p' is:


T_p(a)=(2p_1-a_1,2p_2-a_2)

then, for the point C(-1,3), we have the following:


\begin{gathered} (T_((-2,3))\circ r_x)(C)=(T_((-2,3))\circ r_x)(-1,3)_{}_{} \\ =T_((-2,3))(r_x(-1,3))=T_((-2,3))(-1,-3)=(2(-2)-(-1),2(3)-(-3)) \\ =(-4+1,6+3)=(-3,9) \end{gathered}

therefore, the image of C(-1,3) under the transformations is (-3,9)

User Lorenzo Polidori
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