Question

Let C'P' be the image of CP after a dilation. The equation to calculate the scale factor, k, is _____.

A. k= 1/CP
B. k= C'P'/CP
C. k= CP/C'P'
D. k= 2/C'P'

Answer 1

Option B.
`k=(C'P')/(CP)`

Explanation:

Let C'P' be the image of CP after a dilation. We have to find the equation to calculate the scale factor k.

First we will take an example, if C'P' is the dilated image of CP dilated by a factor of 2 then C'P' = 2×CP will be the equation.

Similarly if CD is enlarged by a factor of k to form C'P' then the equation will be C'P' = kCP

or
`(C'P')/(CP)=k`

Therefore, Option B.
`k=(C'P')/(CP)` is the answer.

Answer 2

After a dilatation: C´P´= CP * k
k = C´P´/ CP
Answer: B)