Math Problem Statement

Use the Squeeze Theorem to evaluate the limit of x^2 * sin(5/x^2) as x approaches 0.

Solution

The image you've uploaded presents a problem about evaluating a limit using the Squeeze Theorem, particularly involving the sine function. Here's a breakdown of the steps and solutions:

  1. Squeeze Theorem Explanation:

    • We are given that f(x)g(x)h(x)f(x) \leq g(x) \leq h(x) for xx in some interval around aa, except possibly at aa.
    • If limxaf(x)=limxah(x)=L\lim_{x \to a} f(x) = \lim_{x \to a} h(x) = L, then limxag(x)=L\lim_{x \to a} g(x) = L.
  2. The specific problem:

    • You are asked to use the Squeeze Theorem to evaluate limx0x2sin(5x2)\lim_{x \to 0} x^2 \sin \left( \frac{5}{x^2} \right).
    • The goal is to find bounds for x2sin(5x2)x^2 \sin \left( \frac{5}{x^2} \right) and then apply the Squeeze Theorem.

Step-by-Step Solution:

Step 1: Recognizing the Bound on Sine Function

  • Recall that for any real number yy, the sine function satisfies: 1sin(y)1-1 \leq \sin(y) \leq 1 Therefore, for y=5x2y = \frac{5}{x^2}, we have: 1sin(5x2)1-1 \leq \sin\left( \frac{5}{x^2} \right) \leq 1

Step 2: Multiplying by x2x^2

  • Now, multiply the inequality by x2x^2, which is nonnegative for all xx. This gives: x2x2sin(5x2)x2-x^2 \leq x^2 \sin\left( \frac{5}{x^2} \right) \leq x^2

Step 3: Applying the Squeeze Theorem

  • From the inequality, we now know that: x2x2sin(5x2)x2-x^2 \leq x^2 \sin\left( \frac{5}{x^2} \right) \leq x^2
  • As x0x \to 0, both x2-x^2 and x2x^2 tend to 0. Hence, by the Squeeze Theorem: limx0x2sin(5x2)=0\lim_{x \to 0} x^2 \sin\left( \frac{5}{x^2} \right) = 0

Conclusion:

  • The limit is 00.

Let me know if you'd like further clarifications on this or help with another part of the problem!

Relative Questions:

  1. How do you identify functions that are appropriate for the Squeeze Theorem?
  2. What are common pitfalls when applying the Squeeze Theorem to trigonometric functions?
  3. Can the Squeeze Theorem be used for limits that approach infinity? How?
  4. What happens if the outer bounds of the Squeeze Theorem don't tend to the same limit?
  5. How does the behavior of sin(1x)\sin \left( \frac{1}{x} \right) change for small values of xx?

Tip:

Always check that the functions on both sides of your inequality have the same limit when using the Squeeze Theorem; otherwise, it cannot be applied.

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Math Problem Analysis

Mathematical Concepts

Limits
Trigonometric Functions
Inequalities

Formulas

Squeeze Theorem: If f(x) ≤ g(x) ≤ h(x) and lim f(x) = lim h(x) = L, then lim g(x) = L

Theorems

Squeeze Theorem

Suitable Grade Level

Grades 11-12, College Calculus