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efgh is rotated 90 degrers clockwise about the origin and then translate it 3 units down if the coordinates of a resultant point is 1,-4 what were the coordinates original point?A. 2,5B.4,5C.3,1D.1,1

User Ndugger
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1 Answer

7 votes

90-degree clockwise rotation transforms the coordinates the following way:


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

Now, after performing 90-degree clockwise rotation, we also move our point 3 units down, meaning, the final coordinates of the point are


(y,-x-3)

Now we are told that the coordinates of the resultant point are


(1,-4)

meaning


\begin{gathered} y=1 \\ -x-3=-4 \\ \end{gathered}

Solving for x gives


\begin{gathered} y=1 \\ x=1 \end{gathered}

Hence, the coordinates of the original point are


(1,1)

which is choice D.

User Guna
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4.2k points