Graph the following functions and compare their similarities and differences.

f(x)=√x and g(x)=^3√x

Which statement below is false?

Responses

both functions have a domain of (−∞,∞)

the graphs intersect at (0, 0) and (1, 1)

both functions are increasing

1 answer

To compare the functions \( f(x) = \sqrt{x} \) and \( g(x) = \sqrt[3]{x} \), let's analyze each function in terms of their domains, ranges, and characteristics.

  1. Domains:

    • \( f(x) = \sqrt{x} \) has a domain of \( [0, \infty) \) since the square root function is defined only for non-negative numbers.
    • \( g(x) = \sqrt[3]{x} \) has a domain of \( (-\infty, \infty) \) because the cube root function is defined for all real numbers.
  2. Intersections:

    • The functions intersect at the points where \( f(x) = g(x) \).
    • For the points you provided:
      • At \( (0, 0) \), both functions yield \( 0 \).
      • At \( (1, 1) \), both functions yield \( 1 \).
    • So, they do indeed intersect at \( (0, 0) \) and \( (1, 1) \).
  3. Increasing/Decreasing:

    • \( f(x) = \sqrt{x} \) is an increasing function for \( x \geq 0 \).
    • \( g(x) = \sqrt[3]{x} \) is also an increasing function for all \( x \).

Now, looking at the statements:

  1. "Both functions have a domain of \( (-\infty, \infty) \)" - This statement is false. \( f(x) = \sqrt{x} \) has a domain of \( [0, \infty) \), not \( (-\infty, \infty) \).

  2. "The graphs intersect at \( (0, 0) \) and \( (1, 1) \)" - This statement is true based on our analysis.

  3. "Both functions are increasing" - This statement is also true as both functions are increasing in their respective domains.

Thus, the false statement is:

"Both functions have a domain of (−∞,∞)".