SOLUTION: Pre-image: A(−4, 2) , B(4, 4) , and C(−1, 2) Image: A′(−2, 1) , B′(2, 2) , and C′(−12, 1) Is the dilation an expansion or cont

Algebra ->  Formulas -> SOLUTION: Pre-image: A(−4, 2) , B(4, 4) , and C(−1, 2) Image: A′(−2, 1) , B′(2, 2) , and C′(−12, 1) Is the dilation an expansion or cont      Log On


   

Question 1047615: Pre-image: A(−4, 2) , B(4, 4) , and C(−1, 2)
Image: A′(−2, 1) , B′(2, 2) , and C′(−12, 1)
Is the dilation an expansion or contraction? What is the scale factor?
Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
i think you meant:

pre-image:
a = -4,2
b = 4,4
c = -1,2

post-image
a' = -2,1
b' = 2,2
c' = -1/2, 1

this would be a contraction.

the scale factor would be 1/2.

a' = 1/2 * a
b' = 1/2 * b
c' = 1/2 * c

the post image is 1/2 times the dimensions of the pre-image.

the center of the dilation is assumes to be the origin.

here's a reference.

http://www.regentsprep.org/regents/math/geometry/gt3/ldilate2.htm