How Do we Graph Dilations?

Aim: How do we Graph Dilations?

A Dilation is a type of transformation that casuse an image to stretch or shrink. It could decrease in size or increase.

•  The scale Factor is the ratio in which the image stretch or shrinks.
• If the factor is greater than 1, then the image will get bigger than the original image.
• If the factor is greater than 0 but less than 1 the image will shrink form the original.
• Multiply the dimensions of the priginal by the scale factors to get the new dimensions of the dilated image.

 Example:
A(-2,-2) --> A'(-4,-4)
B(-1,2) --> B'(-2,4)
C(2,1) --> C' (4,2)
D2

In this figure, it was dilated by 2 from its original image and each point is multiplied by 2.

Some times the image will shrink and this is when the image is dilated by a ratio like

ex: D(1/3) the points will be change from its original to something smaller.

Now try it out:



What are the coordinates of the image of point B under a dilation with center at the origin of scale factor 1/3?

Choose one:
(-1,-3)
(-1,-1)
(-9,-3)
(-9,-9)