Question

Given the point and its image, determine the scale factor. B(2,5) B'(1,2.5) 0 -1/2 02 0-2 O 1/2​

Answer 1

Given:

The point is B(2,5) and its image is B'(1,2.5).

To find:

The scale factor.

Solution:

If a figure is dilated by the scale factor k and (0,0) is the center of then the scale factor is defined as

$k=\dfrac{\text{x-coordinate of the point on image}}{\text{x-coordinate of the corresponding point on the original figure}}$

x-coordinate of point B' is 1 and the x-coordinate of point B is 2. So, the scale factor is

$k=\dfrac{1}{2}$

Therefore, the scale factor is  $\dfrac{1}{2}$ and the correct option is D.