Math Problem Statement

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

Solution

To find the critical points of a function, we need to calculate the derivative of the function f(x)f(x) and set it equal to zero. Let's break this problem down:

Given: f(x)=ex44+10pxf(x) = e^{\frac{x^4}{4} + 10px}

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

The function f(x)f(x) is of the form eg(x)e^{g(x)}, where g(x)=x44+10pxg(x) = \frac{x^4}{4} + 10px. By the chain rule, the derivative of f(x)f(x) is:

f(x)=eg(x)g(x)f'(x) = e^{g(x)} \cdot g'(x)

Now, we need to compute g(x)g'(x), the derivative of g(x)g(x): 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) becomes: f(x)=ex44+10px(x3+10p)f'(x) = e^{\frac{x^4}{4} + 10px} \cdot (x^3 + 10p)

Step 2: Find the critical points

To find the critical points, we set f(x)=0f'(x) = 0. Since the exponential term ex44+10pxe^{\frac{x^4}{4} + 10px} is never zero, we only need to solve:

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

This simplifies to: x3=10px^3 = -10p

Taking the cube root of both sides gives: x=10p3x = \sqrt[3]{-10p}

Final Answer:

The value of xx at which the function has a critical point is x=10p3x = \sqrt[3]{-10p}.

Let me know if you'd like more details or if you have any further questions!

Here are 5 related questions:

  1. How do critical points help in determining the behavior of a function?
  2. What is the importance of using the chain rule in finding derivatives?
  3. How can you determine if the critical point is a maximum or minimum?
  4. What happens when p=0p = 0 in this problem?
  5. How do higher-degree polynomials affect the number of critical points?

Tip: Always double-check if your critical points lead to local maxima or minima by evaluating the second derivative!

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Math Problem Analysis

Mathematical Concepts

Calculus
Derivatives
Critical Points
Exponential Functions

Formulas

f'(x) = e^(x^4/4 + 10px) * (x^3 + 10p)
x^3 + 10p = 0
x = (-10p)^(1/3)

Theorems

Chain Rule

Suitable Grade Level

Undergraduate Calculus