Compare the graphs of f(x)=−x−−√ and g(x)=−x−−√3 . Which of the following features about the graphs is true? (1 point) Responses The graphs have the same ranges. The graphs have the same ranges. The graphs have the same domains. The graphs have the same domains. The graphs are both increasing. The graphs are both increasing. The graphs are both decreasing.

1 answer

Let's analyze the functions \( f(x) = -\sqrt{x} \) and \( g(x) = -\sqrt[3]{x} \).

  1. Domains:

    • For \( f(x) = -\sqrt{x} \): The square root function is defined for \( x \geq 0 \). Therefore, the domain of \( f(x) \) is \( [0, \infty) \).
    • For \( g(x) = -\sqrt[3]{x} \): The cube root function is defined for all \( x \). Thus, the domain of \( g(x) \) is \( (-\infty, \infty) \).
    • Conclusion: The graphs do not have the same domain.
  2. Ranges:

    • For \( f(x) = -\sqrt{x} \): The range is all non-positive real numbers since as \( x \) approaches \( 0 \), \( f(x) \) approaches \( 0 \) and goes to \( -\infty \) as \( x \) increases. So the range is \( (-\infty, 0] \).
    • For \( g(x) = -\sqrt[3]{x} \): The range is also all real numbers since the cube root function can take any value. Therefore, multiplying by -1 gives \( (-\infty, \infty) \).
    • Conclusion: The graphs do not have the same range.
  3. Monotonicity (Increasing/Decreasing):

    • For \( f(x) = -\sqrt{x} \): This function is decreasing on its domain \( [0, \infty) \) because as \( x \) increases, \( -\sqrt{x} \) decreases.
    • For \( g(x) = -\sqrt[3]{x} \): This function is also decreasing for all real \( x \) since as \( x \) increases, \( -\sqrt[3]{x} \) also decreases.
    • Conclusion: Both graphs are decreasing.

Based on the analysis, the true statements are:

  • The graphs have the same ranges. (False)
  • The graphs have the same domains. (False)
  • The graphs are both increasing. (False)
  • The graphs are both decreasing. (True)

Final Answer: The graphs are both decreasing.