Math Problem Statement

limx0(\exponentialE3x1)x\lim_{x\rarr0}\frac{\left(\exponentialE^{3x}-1\right)}{x}

Solution

We are asked to evaluate the limit:

limx0exp(3x)1x\lim_{x \to 0} \frac{\exp(3x) - 1}{x}

Step 1: Apply L'Hopital's Rule

The limit is of the indeterminate form 00\frac{0}{0}, as:

  • exp(3x)1\exp(3x) \to 1 as x0x \to 0,
  • The numerator exp(3x)10\exp(3x) - 1 \to 0,
  • The denominator x0x \to 0.

L'Hopital's Rule is applicable when the limit results in the form 00\frac{0}{0}. It states that:

limxaf(x)g(x)=limxaf(x)g(x)\lim_{x \to a} \frac{f(x)}{g(x)} = \lim_{x \to a} \frac{f'(x)}{g'(x)} if the limit on the right-hand side exists.

Step 2: Differentiate the Numerator and Denominator

We differentiate the numerator and denominator separately.

  • The derivative of the numerator exp(3x)1\exp(3x) - 1 with respect to xx is:

ddx(exp(3x)1)=3exp(3x)\frac{d}{dx}\left(\exp(3x) - 1\right) = 3\exp(3x)

  • The derivative of the denominator xx with respect to xx is:

ddx(x)=1\frac{d}{dx}(x) = 1

Step 3: Apply the Rule

Using L'Hopital's Rule:

limx0exp(3x)1x=limx03exp(3x)1\lim_{x \to 0} \frac{\exp(3x) - 1}{x} = \lim_{x \to 0} \frac{3\exp(3x)}{1}

As x0x \to 0, exp(3x)1\exp(3x) \to 1, so:

limx03exp(3x)1=3×1=3\lim_{x \to 0} \frac{3\exp(3x)}{1} = 3 \times 1 = 3

Thus, the value of the limit is:

3\boxed{3}


Would you like further details on the solution process or any clarifications? Here are some related questions that could deepen the understanding:

  1. What are other indeterminate forms where L'Hopital's Rule can be applied?
  2. How does the exponential function behave as x0x \to 0?
  3. Can this result be generalized for other exponential expressions such as exp(kx)\exp(kx)?
  4. How can we derive the limit using a series expansion for exp(3x)\exp(3x)?
  5. What are the applications of limits involving exponential functions in calculus?

Tip: L'Hopital's Rule can be very useful for indeterminate forms like 00\frac{0}{0} or \frac{\infty}{\infty}. Always check if it applies before trying alternative methods like series expansion.

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Math Problem Analysis

Mathematical Concepts

Limits
Exponential Functions
L'Hopital's Rule

Formulas

L'Hopital's Rule: \lim_{x\to a} \frac{f(x)}{g(x)} = \lim_{x\to a} \frac{f'(x)}{g'(x)}
Exponential function: \exp(kx)

Theorems

L'Hopital's Rule

Suitable Grade Level

Grades 11-12