Math Problem Statement

Find the possible maximum and minimum points for f(x) = e^(1 - sqrt(x^2))

Solution

The function given is:

f(x)=e1x2=e1xf(x) = e^{1 - \sqrt{x^2}} = e^{1 - |x|}

To find the possible maximum and minimum points, we follow these steps:

  1. Take the derivative of f(x)f(x): The first derivative helps us find the critical points, which may correspond to maxima, minima, or saddle points.

f(x)=ddx(e1x)f'(x) = \frac{d}{dx} \left( e^{1 - |x|} \right)

Using the chain rule, the derivative of e1xe^{1 - |x|} involves differentiating the exponent. For x0x \geq 0, x=x|x| = x, and for x<0x < 0, x=x|x| = -x. Therefore, we treat the cases separately.

For x>0x > 0: f(x)=e1x(1)=e1xf'(x) = e^{1 - x} \cdot (-1) = -e^{1 - x}

For x<0x < 0: f(x)=e1+x(1)=e1+xf'(x) = e^{1 + x} \cdot (-1) = -e^{1 + x}

At x=0x = 0, f(x)f'(x) is continuous because f(x)=e1f(x) = e^{1}, and the absolute value function is non-differentiable at x=0x = 0, but the first derivative from both sides approaches the same value.

  1. Find the critical points: Set f(x)=0f'(x) = 0.

Since e1xe^{1 - |x|} is never zero (the exponential function is always positive), the derivative does not give any zeroes. Therefore, there are no critical points where f(x)=0f'(x) = 0.

However, we check the boundary behavior and analyze the function's behavior as xx \to \infty and xx \to -\infty.

  1. Analyze the function at boundary points:
  • As xx \to \infty, f(x)=e1x0f(x) = e^{1 - |x|} \to 0.
  • As xx \to -\infty, f(x)=e1x0f(x) = e^{1 - |x|} \to 0.
  • At x=0x = 0, f(0)=e1f(0) = e^{1}, which gives the highest value of the function.

Thus, the function has a global maximum at x=0x = 0, where f(0)=e1f(0) = e^1, and the function tends to 0 as xx \to \infty or xx \to -\infty, indicating that it has no other critical points or local minima.

Conclusion:

  • Global Maximum: At x=0x = 0, f(x)=e1f(x) = e^1.
  • The function tends to 0 as x|x| \to \infty, with no local minima.

Would you like further details or clarifications?

Here are 5 related questions for further exploration:

  1. How would the behavior of the function change if the exponent were altered to e1x2e^{1 - x^2}?
  2. What happens to the derivative and critical points if the function involves higher powers of xx?
  3. Can we classify whether the maximum found is an absolute or relative maximum?
  4. How does the absolute value function x|x| affect the continuity and differentiability of functions?
  5. What is the significance of boundary behavior when evaluating limits for xx \to \infty?

Tip: When taking derivatives of functions involving absolute values, always split the function into different cases based on the sign of the variable.

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Math Problem Analysis

Mathematical Concepts

Calculus
Derivatives
Exponential Functions

Formulas

f(x) = e^(1 - |x|)
f'(x) = -e^(1 - x) for x > 0
f'(x) = -e^(1 + x) for x < 0

Theorems

Chain Rule
Critical Points
Maxima and Minima Theorem

Suitable Grade Level

Grades 11-12 or Early University