Graph Quadrilateral ABCD whose vertex matrix is shown below. Then graph the dilation of Quadrilateral ABCD with a scale factor of 3 on the same coordinate grid.
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Answer:
The coordinates of the vertices of the dilated figure are:
A' is (-3 , 6), B' is (15 , 15), C' is (15 , 9), D' is (-12 , -3) ⇒ the answer is (a)
Step-by-step explanation:
* Lets study the matrix of the dilation
- If we dilate any point by scale factor k we multiply the
coordinates of the point by k
- The matrix of the dilation by scale factor k is
[tex]\left[\begin{array}{cc}k&0\\0&k\end{array}\right][/tex]
* Now lets solve the problem
- We will multiply the matrix of dilation by the matrix of the
vertices of the quadrilateral
- The dimension of the matrix of the dilation is 2×2 and the
dimension of the matrix of the vertices of the quadrilateral
is 2×4 then the dimension of the matrix of the image of the
quadrilateral is 2×4
∵ The scale factor is 3
∴ The matrix of dilation is [tex]\left[\begin{array}{cc}3&0\\0&3\end{array}\right][/tex]
∵ The matrix of the vertices of the quadrilateral is
[tex]\left[\begin{array}{cccc}-1&5&5&-4\\2&5&3&-1\end{array}\right][/tex]
∴ The image of the quadrilateral is :
[tex]\left[\begin{array}{cc}3&0\\0&3\end{array}\right]\left[\begin{array}{cccc}-1&5&5&-4\\2&5&3&-1\end{array}\right]=[/tex]
[tex]\left[\begin{array}{cccc}(3)(-1)+(0)(2)&(3)(5)+(0)(5)&(3)(5)+(0)(3)&(3)(-4)+(0)(-1)\\(0)(-1)+(3)(2)&(0)(5)+(3)(5)&(0)(5)+(3)(3)&(0)(-4)+(3)(-1)\end{array}\right][/tex]
[tex]\left[\begin{array}{cccc}-3&15&15&-12\\6&15&9&-3\end{array}\right][/tex]
∴ The image of point A' is (-3 , 6)
∴ The image of point B' is (15 , 15)
∴ The image of point C' is (15 , 9)
∴ The image of point D' is (-12 , -3)
* The answer is figure (a)