Math Problem Statement

Solve the following limits using L'Hôpital's Rule: (1) lim_{x→∞} [(x+3) / (√(x² - 5) - 2)], (2) lim_{x→∞} [(5x⁴ - 4x² - 1) / (10 - x - 9x³)].

Solution

The image contains mathematical problems requiring the application of L'Hôpital's Rule. Here's the step-by-step solution for the limits provided:

Problem 2:

limxx+3x252\lim_{x \to \infty} \frac{x + 3}{\sqrt{x^2 - 5} - 2}

Solution:

  1. Simplify the denominator: x25\sqrtTheximageyou2uploadedcontainsmathematical=xexpressions involvingquadlimits andLHtext(forlargex).\sqrt{x^2 - 5} \approx \sqrtThe{x image^ you2 uploaded} contains mathematical = x expressions \ involvingquad limits \ and L'Htext{(for large } x\text{)}.

    Substituting this approximation:

The first part of the image includes L'Hopital's Rule:

L'Hopital's Rule is used to evaluate limits of indeterminate forms like 0/0 or ∞/∞. The rule states: [ \lim_{x \to a} \frac{f(x)}{g(x)} = \lim_{x \to a} \frac{f'(x)}{g'(x)}$$ if the limit on the right side exists.

Now, let's analyze the problems:

1) (\lim_{x \to 3} \frac{x+3}{\sqrt{x^2 - }5} - 2}\ \approx \frac{x + 3}{x - 2}.

]

2.) We are looking for the limit as xDividex Divide approaches 3 for the expression x+3x252\frac{x+3}{\sqrt{x^2 - 5} - 2}. Since direct substitution results numerator in a 00\frac{0}{0} indeterminate form, L'Hopital and's Rule should be applied denominator.

2) limx05x44x2110x9x3\lim_{x \to 0} \frac{5x^4 - 4x^2 - 1}{10 - x - 9x^3}

For this limit, direct substitution also yields by xx to simplify: x+3x2=1+3x12x.\frac{x + 3}{x - 2} = \frac{1 + \frac{3}{x}}{1 - \frac{2}{x}}.

  1. As a \(\frac{0}{0} form, so applying L'Hopital'sx Rule is necessary.

\to \infty),Let me the terms now work through the \ steps of solving these limits. Would(\ youfrac like{ me to solve them in3 detail for you?}{x}) and 2x\frac{2}{x} approach 0: limx1+3x12x=1+010=1.\lim_{x \to \infty} \frac{1 + \frac{3}{x}}{1 - \frac{2}{x}} = \frac{1 + 0}{1 - 0} = 1.

Final Answer: limxx+3x252=1.\lim_{x \to \infty} \frac{x + 3}{\sqrt{x^2 - 5} - 2} = 1.


Problem 4:

limx5x44x2110x9x3\lim_{x \to \infty} \frac{5x^4 - 4x^2 - 1}{10 - x - 9x^3}

Solution:

  1. Identify the highest power of xx in the numerator and denominator:

    • Numerator: 5x45x^4,
    • Denominator: 9x3-9x^3.
  2. Factor out x4x^4 from the numerator and x3x^3 from the denominator: 5x44x2110x9x3=x4(54x21x4)x3(9+10x31x2).\frac{5x^4 - 4x^2 - 1}{10 - x - 9x^3} = \frac{x^4\left(5 - \frac{4}{x^2} - \frac{1}{x^4}\right)}{x^3\left(-9 + \frac{10}{x^3} - \frac{1}{x^2}\right)}.

  3. Simplify by canceling x3x^3: 5x49x3=5x9 with the remaining terms approaching 0 as x.\frac{5x^4}{-9x^3} = \frac{5x}{-9} \text{ with the remaining terms approaching 0 as } x \to \infty.

  4. As xx \to \infty:

    • The numerator is dominated by 5x45x^4,
    • The denominator is dominated by 9x3-9x^3,
    • The other terms vanish.

Final Answer: limx5x44x2110x9x3=.\lim_{x \to \infty} \frac{5x^4 - 4x^2 - 1}{10 - x - 9x^3} = \infty.


Would you like more detailed steps or explanations for these problems?

Related Questions:

  1. What is the application of L'Hôpital's Rule in indeterminate forms?
  2. How does factoring help in simplifying limits as xx \to \infty?
  3. When do we approximate terms with the highest degree of xx?
  4. How can we use dominant terms to estimate limits more efficiently?
  5. Can L'Hôpital's Rule be applied directly to problem 4?

Tip: Always analyze the dominant terms when solving limits as xx \to \infty. This simplifies complex expressions significantly.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Calculus
Limits
Indeterminate Forms
Rational Expressions

Formulas

L'Hôpital's Rule: lim_{x→a} [f(x)/g(x)] = lim_{x→a} [f'(x)/g'(x)]
Simplification of radicals: √(x² + a) ≈ x for large x

Theorems

L'Hôpital's Rule

Suitable Grade Level

Grades 11-12, College Calculus I