Math Problem Statement

Describe the x-values at which the function y = -5√(2x + 9) is differentiable.

Solution

The given function is y=2x+95y = -\sqrt[5]{2x + 9}.

To determine where the function is differentiable:

  1. Domain restrictions:

    • The expression inside the fifth root must be non-negative because roots of odd degrees (like 5) are defined for all real numbers.
    • However, to avoid undefined situations or complex values for the function, we check: 2x+902x + 9 \geq 0 Solving this: x92=4.5x \geq -\frac{9}{2} = -4.5 So the domain of the function is x4.5x \geq -4.5.
  2. Differentiability:

    • A function is differentiable where it is both continuous and has a well-defined slope (no sharp corners or vertical tangents).
    • For a function involving a root, differentiability is lost at points where the slope becomes vertical or undefined.
    • For y=2x+95y = -\sqrt[5]{2x + 9}, differentiability depends on whether the derivative becomes infinite at any point.

The graph shows that the curve behaves smoothly for x>4.5x > -4.5, but at x=4.5x = -4.5, the slope approaches vertical (sharp bend), which indicates the function is not differentiable at x=4.5x = -4.5. It is only differentiable for x>4.5x > -4.5.

Conclusion:

The function is differentiable for (4.5,)(-4.5, \infty).

Would you like further details, or have any other questions? Here are five related questions to consider:

  1. What is the derivative of the function y=2x+95y = -\sqrt[5]{2x + 9}?
  2. How do you determine if a function is differentiable at a specific point?
  3. Can you explain the relationship between continuity and differentiability?
  4. What happens to the derivative at points where a function has a vertical tangent?
  5. How would you graph the derivative of this function?

Tip: Differentiability implies continuity, but continuity does not always imply differentiability. Always check the behavior of the function at key points!

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Differentiability
Domain Restrictions
Roots and Powers

Formulas

y = -√5(2x + 9)
Derivative of root functions

Theorems

Differentiability conditions
Domain restrictions for roots

Suitable Grade Level

Grades 11-12