Answer:
The coordinates of the vertices of the dilated figure are:
A' is (-2 , 4), B' is (4 , 8), C' is (4 , -2), D' is (-2 , -6) ⇒ the answer is (d)
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
![\left[\begin{array}{ccc}k&0\\0&k\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Dk%260%5C%5C0%26k%5Cend%7Barray%7D%5Cright%5D)
* 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 2
∴ The matrix of dilation is ![\left[\begin{array}{cc}2&0\\0&2\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D2%260%5C%5C0%262%5Cend%7Barray%7D%5Cright%5D)
∵ The matrix of the vertices of the quadrilateral is
![\left[\begin{array}{cccc}-1&2&2&-1\\2&4&-1&-3\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcccc%7D-1%262%262%26-1%5C%5C2%264%26-1%26-3%5Cend%7Barray%7D%5Cright%5D)
∴ The image of the quadrilateral is :
![\left[\begin{array}{cc}2&0\\0&2\end{array}\right]\left[\begin{array}{cccc}-1&2&2&-1\\2&4&-1&-3\end{array}\right]=](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D2%260%5C%5C0%262%5Cend%7Barray%7D%5Cright%5D%5Cleft%5B%5Cbegin%7Barray%7D%7Bcccc%7D-1%262%262%26-1%5C%5C2%264%26-1%26-3%5Cend%7Barray%7D%5Cright%5D%3D)
![\left[\begin{array}{cccc}(2)(-1)+(0)(2)&(2)(2)+(0)(4)&(2)(2)+(0)(-1)&(2)(-1)+(0)(-3)\\(0)(-1)+(2)(2)&(0)(2)+(2)(4)&(0)(2)+(2)(-1)&(0)(-1)+(2)(-3)\end{array}\right]=](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcccc%7D%282%29%28-1%29%2B%280%29%282%29%26%282%29%282%29%2B%280%29%284%29%26%282%29%282%29%2B%280%29%28-1%29%26%282%29%28-1%29%2B%280%29%28-3%29%5C%5C%280%29%28-1%29%2B%282%29%282%29%26%280%29%282%29%2B%282%29%284%29%26%280%29%282%29%2B%282%29%28-1%29%26%280%29%28-1%29%2B%282%29%28-3%29%5Cend%7Barray%7D%5Cright%5D%3D)
![\left[\begin{array}{cccc}-2&4&4&-2\\4&8&-2&-6\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcccc%7D-2%264%264%26-2%5C%5C4%268%26-2%26-6%5Cend%7Barray%7D%5Cright%5D)
∴ The image of point A' is (-2 , 4)
∴ The image of point B' is (4 , 8)
∴ The image of point C' is (4 , -2)
∴ The image of point D' is (-2 , -6)
* The right answer is figure (d)