Skip to main content
Ch. 7 - Transcendental Functions
Hass - Thomas' Calculus 15th Edition
Hass15th EditionThomas' CalculusISBN: 9780137616077Not the one you use?Change textbook
Chapter 7, Problem 7.PE.99

Use l’Hôpital’s Rule to find the limits in Exercises 85–108.
99. lim(x→0) (2^sin(x) - 1)/(e^x - 1)

Verified step by step guidance
1
First, recognize that the limit is of the form \( \frac{0}{0} \) when \( x \to 0 \), since \( 2^{\sin(0)} - 1 = 2^0 - 1 = 0 \) and \( e^0 - 1 = 0 \). This means l'Hôpital's Rule can be applied.
Apply l'Hôpital's Rule by differentiating the numerator and denominator separately with respect to \( x \).
Differentiate the numerator: \( \frac{d}{dx} \left( 2^{\sin(x)} - 1 \right) = \frac{d}{dx} \left( 2^{\sin(x)} \right) = 2^{\sin(x)} \cdot \ln(2) \cdot \cos(x) \) using the chain rule.
Differentiate the denominator: \( \frac{d}{dx} (e^x - 1) = e^x \).
Rewrite the limit using these derivatives: \[ \lim_{x \to 0} \frac{2^{\sin(x)} \cdot \ln(2) \cdot \cos(x)}{e^x} \]. Then, evaluate this new limit by substituting \( x = 0 \).

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
3m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

l’Hôpital’s Rule

l’Hôpital’s Rule is a method for evaluating limits that result in indeterminate forms like 0/0 or ∞/∞. It states that the limit of a ratio of functions can be found by taking the limit of the ratio of their derivatives, provided certain conditions are met.
Recommended video:

Limits and Indeterminate Forms

Understanding limits involves analyzing the behavior of functions as the input approaches a specific value. Indeterminate forms such as 0/0 occur when direct substitution does not yield a clear limit, signaling the need for alternative techniques like l’Hôpital’s Rule.
Recommended video:
05:50
One-Sided Limits

Derivatives of Exponential and Trigonometric Functions

Calculating the derivatives of functions like 2^sin(x) and e^x is essential for applying l’Hôpital’s Rule. This involves using the chain rule and the fact that the derivative of a^u is a^u ln(a) times the derivative of u, and the derivative of e^x is e^x.
Recommended video:
06:35
Derivatives of Other Inverse Trigonometric Functions