The following ordered pairs came from a function transformation. The original ordered pair is (4,9), and the transformation ordered pair is (2,9). Which of the following correctly identifies the value of k and describes whether the dilation is a horizontal compression or stretch

k =2; stretch
k = 0,5; compression
k = 2; compression
k = 9.5; stretch

1 answer

To determine the value of \( k \) and the type of transformation, we need to compare the \( x \)-coordinates of the original point and the transformed point.

The original ordered pair is \( (4, 9) \) and the transformed ordered pair is \( (2, 9) \). The \( y \)-coordinates remain the same, indicating that there is no vertical transformation, only a horizontal transformation.

The transformation affects the \( x \)-coordinate from \( 4 \) to \( 2 \). The dilation factor \( k \) can be calculated using the formula for horizontal dilation:

\[ \text{New } x = \frac{\text{Old } x}{k} \]

Substituting the values, we have:

\[ 2 = \frac{4}{k} \]

To solve for \( k \):

  1. Multiply both sides by \( k \):

\[ 2k = 4 \]

  1. Divide both sides by \( 2 \):

\[ k = 2 \]

Since the value of \( k \) is 2, this indicates a horizontal compression. A horizontal compression occurs when \( k > 1 \).

Thus, the correct identification from the options provided is:

k = 2; compression