Math Problem Statement

\int_0^{\infty}\!\exponentialE^2^{x-3}x\,\mathrm{d}x

Solution

The given integral is:

I=0e2x3xdxI = \int_0^{\infty} e^{2^{x-3}} x \, \mathrm{d}x

Step 1: Analyze the integrand

The integrand involves an exponential function with a base that is a function of xx. Let's rewrite the integrand more clearly:

I=0xe2x3dxI = \int_0^{\infty} x \, e^{2^{x-3}} \, \mathrm{d}x

Step 2: Substitution for simplification

To simplify the expression, we perform a substitution. Let’s define:

u=x3so thatdu=dxandx=u+3u = x - 3 \quad \text{so that} \quad du = dx \quad \text{and} \quad x = u + 3

This transforms the integral into:

I=3(u+3)e2uduI = \int_{-3}^{\infty} (u+3) e^{2^u} \, du

Step 3: Break the integral into parts

We can now split the integral into two parts:

I=3ue2udu+33e2uduI = \int_{-3}^{\infty} u e^{2^u} \, du + 3 \int_{-3}^{\infty} e^{2^u} \, du

Step 4: Evaluate the integrals

  1. First Integral: 3ue2udu\int_{-3}^{\infty} u e^{2^u} \, du

    This integral does not have an elementary antiderivative, and it is difficult to solve in a straightforward way. For this type of problem, one might resort to numerical integration or approximate methods.

  2. Second Integral: 3e2udu\int_{-3}^{\infty} e^{2^u} \, du

    This is also a complicated integral, and it doesn't have an elementary form. Numerical methods would typically be used here as well.

Conclusion

The integral involves functions that do not have simple antiderivatives. Therefore, evaluating this integral would require numerical methods or approximation techniques.

Would you like help with performing a numerical approximation or exploring further techniques? Also, here are some related questions you might be interested in:

  1. How to handle integrals involving exponential functions with variable exponents?
  2. What numerical methods are available for evaluating difficult integrals like this one?
  3. How do we use series expansions for approximating complex integrals?
  4. What are common approaches to solving integrals with no closed-form solution?
  5. How do different substitution techniques help simplify integrals?

Tip: When facing difficult integrals, especially with complex exponentials, numerical methods like Simpson's Rule, Trapezoidal Rule, or using software like Wolfram Mathematica or Python’s SciPy library can provide accurate approximations.

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Math Problem Analysis

Mathematical Concepts

Integral Calculus
Exponential Functions
Substitution Method
Numerical Integration

Formulas

\int_0^{\infty} x e^{2^{x-3}} \mathrm{d}x
Substitution: u = x - 3

Theorems

Substitution in integrals
Numerical methods for difficult integrals

Suitable Grade Level

Graduate/Advanced Undergraduate