Compare the average rates of change for the graphed square root function p(x)=x+4−−−−√ and the cube root function f(x)=x+4−−−−√3 over the interval [−4,−3] . (1 point) Responses The functions have the same average rate of change of 1. The functions have the same average rate of change of 1. The functions have the same average rate of change of 0. The functions have the same average rate of change of 0. The cube root function has the greater average rate of change. The cube root function has the greater average rate of change. The square root function has the greater average rate of change. The square root function has the greater average rate of change.

1 answer

To compare the average rates of change of the functions \( p(x) = \sqrt{x + 4} \) (square root function) and \( f(x) = \sqrt[3]{x + 4} \) (cube root function) over the interval \([-4, -3]\), we first calculate the values of the functions at the endpoints of the interval.

  1. Calculating \( p(x) = \sqrt{x + 4} \):

    • At \( x = -4 \): \[ p(-4) = \sqrt{-4 + 4} = \sqrt{0} = 0 \]

    • At \( x = -3 \): \[ p(-3) = \sqrt{-3 + 4} = \sqrt{1} = 1 \]

    Therefore, the average rate of change of \( p(x) \) over the interval \([-4, -3]\) is calculated as follows: \[ \text{Average Rate of Change of } p(x) = \frac{p(-3) - p(-4)}{-3 - (-4)} = \frac{1 - 0}{-3 + 4} = \frac{1}{1} = 1 \]

  2. Calculating \( f(x) = \sqrt[3]{x + 4} \):

    • At \( x = -4 \): \[ f(-4) = \sqrt[3]{-4 + 4} = \sqrt[3]{0} = 0 \]

    • At \( x = -3 \): \[ f(-3) = \sqrt[3]{-3 + 4} = \sqrt[3]{1} = 1 \]

    Therefore, the average rate of change of \( f(x) \) over the interval \([-4, -3]\) is calculated as follows: \[ \text{Average Rate of Change of } f(x) = \frac{f(-3) - f(-4)}{-3 - (-4)} = \frac{1 - 0}{-3 + 4} = \frac{1}{1} = 1 \]

Both functions have an average rate of change of 1 over the interval \([-4, -3]\).

Conclusion: The functions have the same average rate of change of 1.