Math Problem Statement

For what value of x does the function f(x) = e^(x^4/4 + 10px) have a critical point if p is a parameter?

Solution

The problem asks for the value of xx at which the function f(x)=ex4/4+10pxf(x) = e^{x^4/4 + 10px} has a critical point, where pp is a parameter.

Step 1: Find the derivative of f(x)f(x)

To find the critical points, we first need to take the derivative of f(x)f(x). Since f(x)=eg(x)f(x) = e^{g(x)}, where g(x)=x44+10pxg(x) = \frac{x^4}{4} + 10px, we apply the chain rule.

f(x)=ddx(eg(x))=eg(x)g(x)f'(x) = \frac{d}{dx}\left( e^{g(x)} \right) = e^{g(x)} \cdot g'(x)

Next, we calculate g(x)g'(x). The derivative of g(x)g(x) is:

g(x)=ddx(x44+10px)=x3+10pg'(x) = \frac{d}{dx} \left( \frac{x^4}{4} + 10px \right) = x^3 + 10p

Thus, the derivative of f(x)f(x) is:

f(x)=ex4/4+10px(x3+10p)f'(x) = e^{x^4/4 + 10px} \cdot (x^3 + 10p)

Step 2: Set the derivative equal to zero

Critical points occur when f(x)=0f'(x) = 0. Since ex4/4+10pxe^{x^4/4 + 10px} is never zero (the exponential function is always positive), we set the other factor equal to zero:

x3+10p=0x^3 + 10p = 0

Step 3: Solve for xx

Solving for xx:

x3=10px^3 = -10p

x=10p3x = -\sqrt[3]{10p}

Thus, the critical point occurs at x=10p3x = -\sqrt[3]{10p}.


Would you like more details or have any further questions on this? Here are some related questions to explore:

  1. What are inflection points, and how do you find them for the same function?
  2. How does the value of pp affect the location of the critical point?
  3. How would you classify the critical point as a maximum, minimum, or saddle point?
  4. Can there be multiple critical points if we modify the function in a certain way?
  5. What would change in the process if the function was f(x)=ex6/6+10pxf(x) = e^{x^6/6 + 10px}?

Tip: Critical points occur where the derivative is zero or undefined. For exponential functions, the factor inside the exponential never becomes zero, so focus on the remaining terms!

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Calculus
Differentiation
Critical Points
Exponential Functions

Formulas

Derivative of exponential function f(x) = e^g(x) is f'(x) = e^g(x) * g'(x)
Chain Rule

Theorems

Critical Point Theorem

Suitable Grade Level

Undergraduate Calculus