Select the coordinates A′ and B′ after dilation of the line segment AB with a scale factor of 1/3 , centered at the origin where the endpoints are A(−6,3) and B(−12,9) .(1 point) what were the original coordinates?

1 answer

To find the dilated coordinates \( A' \) and \( B' \) of the line segment \( AB \) after applying a dilation with a scale factor of \( \frac{1}{3} \) centered at the origin, we can use the dilation formula:

\[ A' = (k \cdot x_A, k \cdot y_A) \] \[ B' = (k \cdot x_B, k \cdot y_B) \]

where \( k \) is the scale factor, and \( (x_A, y_A) \) and \( (x_B, y_B) \) are the coordinates of points \( A \) and \( B \).

Given:

  • \( A(-6, 3) \)
  • \( B(-12, 9) \)
  • Scale factor \( k = \frac{1}{3} \)

Now, applying the formula:

For point \( A' \): \[ A' = \left(\frac{1}{3} \cdot (-6), \frac{1}{3} \cdot 3\right) = \left(-2, 1\right) \]

For point \( B' \): \[ B' = \left(\frac{1}{3} \cdot (-12), \frac{1}{3} \cdot 9\right) = \left(-4, 3\right) \]

Thus, the dilated coordinates after applying the scale factor are:

  • \( A'(-2, 1) \)
  • \( B'(-4, 3) \)

The original coordinates are:

  • \( A(-6, 3) \)
  • \( B(-12, 9) \)