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The vertices of a figure are given. Find the coordinates of the figure after the transformations given.

J(1,1),K(3,4),L(5,1)
J(1,1),K(3,4),L(5,1)
Rotate 90° clockwise about the origin. Then dilate with respect to the origin using a scale factor of 3.
What are the coordinates for the final figure?

1 Answer

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Final answer:

The coordinates for the final figure after rotating 90° clockwise about the origin and dilating with respect to the origin using a scale factor of 3 are J''(-3,3), K''(-12,9), L''(-3,15).

Step-by-step explanation:

To find the coordinates of the figure after the given transformations, we first need to rotate the figure 90° clockwise about the origin. To do this, we can use the rotation matrix:

$$ \begin{bmatrix} \cos(\theta) & -\sin(\theta) \\ \sin(\theta) & \cos(\theta) \end{bmatrix} $$

Since we are rotating 90° clockwise, our angle of rotation will be -90°. Plugging in the coordinates of each vertex of the figure into the rotation matrix, we get:

$$ \begin{align*} J' &= (1,1) \cdot \begin{bmatrix} \cos(-90°) & -\sin(-90°) \\ \sin(-90°) & \cos(-90°) \end{bmatrix} = (1,1) \cdot \begin{bmatrix} 0 & 1 \\ -1 & 0 \end{bmatrix} = (-1,1) \\ K' &= (3,4) \cdot \begin{bmatrix} \cos(-90°) & -\sin(-90°) \\ \sin(-90°) & \cos(-90°) \end{bmatrix} = (3,4) \cdot \begin{bmatrix} 0 & 1 \\ -1 & 0 \end{bmatrix} = (-4,3) \\ L' &= (5,1) \cdot \begin{bmatrix} \cos(-90°) & -\sin(-90°) \\ \sin(-90°) & \cos(-90°) \end{bmatrix} = (5,1) \cdot \begin{bmatrix} 0 & 1 \\ -1 & 0 \end{bmatrix} = (-1,5) \end{align*} $$

After rotating the figure, we need to dilate it with respect to the origin using a scale factor of 3. To do this, we simply multiply the coordinates of each vertex by the scale factor:

$$ \begin{align*} J'' &= (-1,1) \cdot 3 = (-3,3) \\ K'' &= (-4,3) \cdot 3 = (-12,9) \\ L'' &= (-1,5) \cdot 3 = (-3,15) \end{align*} $$

Therefore, the coordinates for the final figure after the given transformations are:

$$ J''(-3,3), K''(-12,9), L''(-3,15) $$

User TG Gowda
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