Math Problem Statement

Use L'Hôpital's Rule to evaluate the limit: lim (x→0) (sin 5x) / x

Solution

To evaluate the limit using L'Hôpital's Rule, let's proceed with the given expression:

limx0sin5xx\lim_{{x \to 0}} \frac{\sin 5x}{x}

Step 1: Verify the Indeterminate Form

As x0x \to 0:

  • The numerator sin5x0\sin 5x \to 0,
  • The denominator x0x \to 0.

This creates the indeterminate form 00\frac{0}{0}, which allows us to apply L'Hôpital's Rule.

Step 2: Apply L'Hôpital's Rule

According to L'Hôpital's Rule, if we have an indeterminate form 00\frac{0}{0}, we can differentiate the numerator and the denominator separately:

  1. Differentiate the numerator: ddx(sin5x)=5cos5x\frac{d}{dx}(\sin 5x) = 5 \cos 5x.
  2. Differentiate the denominator: ddx(x)=1\frac{d}{dx}(x) = 1.

The limit then becomes:

limx05cos5x1\lim_{{x \to 0}} \frac{5 \cos 5x}{1}

Step 3: Substitute x=0x = 0

Now, substitute x=0x = 0:

5cos5(0)=5cos0=5×1=55 \cos 5(0) = 5 \cos 0 = 5 \times 1 = 5

Final Answer

limx0sin5xx=5\lim_{{x \to 0}} \frac{\sin 5x}{x} = 5

Would you like further clarification or details on any of the steps?

Related Questions:

  1. How would the limit change if we evaluated limx0sinkxx\lim_{{x \to 0}} \frac{\sin kx}{x} for any constant kk?
  2. Can we apply L'Hôpital's Rule to solve limx0sinxx2\lim_{{x \to 0}} \frac{\sin x}{x^2}?
  3. What is the result of limx0tan5xx\lim_{{x \to 0}} \frac{\tan 5x}{x}?
  4. Why is L'Hôpital's Rule applicable only in certain indeterminate forms?
  5. How does the result differ if we calculate limx0sin5x2x\lim_{{x \to 0}} \frac{\sin 5x}{2x}?

Tip:

When using L'Hôpital's Rule, always verify that the limit initially presents an indeterminate form like 00\frac{0}{0} or \frac{\infty}{\infty} before proceeding.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Calculus
Limits
L'Hôpital's Rule
Trigonometric Limits

Formulas

L'Hôpital's Rule
Derivative of sin(x)

Theorems

L'Hôpital's Rule

Suitable Grade Level

College Calculus