A(9,9) B(6,6) A'(3,3) B'(2,2)

determine the scale factor used in the dilation of line AB, with a center point of dilation at the origin.
a 3
b -1/3
c 1/3
d -3

1 answer

To determine the scale factor used in the dilation of line AB, we can compare the distances between the points before and after dilation.

Let's calculate the distance between points A and B:

AB = √((6-9)^2 + (6-9)^2)
= √((-3)^2 + (-3)^2)
= √(9 + 9)
= √18

Now let's calculate the distance between points A' and B':

A'B' = √((2-3)^2 + (2-3)^2)
= √((-1)^2 + (-1)^2)
= √(1 + 1)
= √2

The scale factor is given by the ratio of the distances after and before dilation:

Scale factor = A'B' / AB
= (√2) / (√18)
= (√2) / (√(9 * 2))
= (√2) / (√9 * √2)
= (√2) / (3 * √2)
= 1 / 3

Therefore, the scale factor used in the dilation of line AB is 1/3.

The correct answer is c) 1/3.