Which of the following describes transformation(s) of the function h(x)=|−8/7x|?(1 point)

a horizontal stretch by a factor of 8/7

a horizontal compression by a factor of 7/8

a horizontal stretch by a factor of 8/7 and a reflection across the y-axis

a horizontal compression by a factor of 7/8 and a reflection across the y-axis

1 answer

To analyze the function \( h(x) = |-\frac{8}{7}x| \), let's break it down:

  1. The absolute value function \( |x| \) is being transformed by a factor of \( -\frac{8}{7} \) for \( x \).
  2. The negative sign indicates a reflection across the y-axis, because the transformation involves \( -x \).
  3. The factor \( \frac{8}{7} \) indicates that the function is stretched horizontally.

Now, let's clarify the stretch or compression:

  • A normal transformation for a function \( f(kx) \) causes a horizontal compression if \( |k| > 1 \) and a horizontal stretch if \( |k| < 1 \).
  • The function term here is \( -\frac{8}{7}x \), which we can treat as \( f(-\frac{8}{7}x) \).
    • Since \(\frac{8}{7} > 1\), it implies a compression because of the overall \( -x \) aspect.

Let’s check the options given:

  1. A horizontal stretch by a factor of \( \frac{8}{7} \) - Incorrect (we have a compression).
  2. A horizontal compression by a factor of \( \frac{7}{8} \) - Correct.
  3. A horizontal stretch by a factor of \( \frac{8}{7} \) and a reflection across the y-axis - Incorrect.
  4. A horizontal compression by a factor of \( \frac{7}{8} \) and a reflection across the y-axis - Correct.

Thus, the correct descriptions of the transformation(s) of the function \( h(x) = |-\frac{8}{7}x| \) are:

  1. A horizontal compression by a factor of \( \frac{7}{8} \) (option 2 is correct).
  2. A reflection across the y-axis (part of option 4).

Therefore, the final answer is:

A horizontal compression by a factor of \( \frac{7}{8} \) and a reflection across the y-axis.