Does the graph of the function y=3^3√x−1−−−−−show that the function is increasing or decreasing?

Option 1: increasing

Option 2: decreasing

(1 point)
The correct answer is option
.

1 answer

To determine whether the function \( y = 3\sqrt[3]{x} - 1 \) is increasing or decreasing, we should analyze its derivative.

  1. Find the derivative of the function: To find the derivative \( y' \): \[ y = 3\sqrt[3]{x} - 1 = 3x^{1/3} - 1 \] Applying the power rule, the derivative is: \[ y' = 3 \cdot \frac{1}{3} x^{-2/3} = x^{-2/3} \] Thus, \[ y' = \frac{1}{x^{2/3}} \]

  2. Analyze the sign of the derivative: The expression \( \frac{1}{x^{2/3}} \) is positive for all \( x > 0 \) (since \( x^{2/3} \) is positive).

  3. Conclusion: Since the derivative is positive for \( x > 0 \), the function is increasing on that interval.

  4. Final answer: The correct answer is option 1: increasing.