Math Problem Statement

apa jawabannya

Tentukan nilai dari \( \lim_{x \to 0} \frac{7 \sin\left( \frac{1}{3} x \right)}{\tan\left( \frac{1}{2} x \right)} \).

Solution

The given problem asks to determine the limit:

limx07sin(13x)tan(12x).\lim_{x \to 0} \frac{7 \sin \left( \frac{1}{3} x \right)}{\tan \left( \frac{1}{2} x \right)}.

Step-by-step solution:

  1. Use small-angle approximations: For small values of xx, the following approximations hold:

    • sinxx\sin x \approx x,
    • tanxx\tan x \approx x.
  2. Apply the approximations: As x0x \to 0, we can approximate sin(13x)\sin\left( \frac{1}{3} x \right) and tan(12x)\tan\left( \frac{1}{2} x \right): sin(13x)13xandtan(12x)12x.\sin\left( \frac{1}{3} x \right) \approx \frac{1}{3} x \quad \text{and} \quad \tan\left( \frac{1}{2} x \right) \approx \frac{1}{2} x.

  3. Substitute these into the limit expression: limx07sin(13x)tan(12x)=limx0713x12x.\lim_{x \to 0} \frac{7 \sin \left( \frac{1}{3} x \right)}{\tan \left( \frac{1}{2} x \right)} = \lim_{x \to 0} \frac{7 \cdot \frac{1}{3} x}{\frac{1}{2} x}.

  4. Simplify the expression: The xx terms cancel out: =71312=723=143.= 7 \cdot \frac{\frac{1}{3}}{\frac{1}{2}} = 7 \cdot \frac{2}{3} = \frac{14}{3}.

Thus, the value of the limit is 143=423\frac{14}{3} = 4 \frac{2}{3}.

Final answer:

The correct answer is 4234 \frac{2}{3}, which corresponds to the first option.


Would you like further details on any part of the solution? Here are some related questions you could explore:

  1. How can small-angle approximations be derived?
  2. What are the conditions for using approximations in limit problems?
  3. Can L'Hopital's Rule be used in solving this type of limit?
  4. How do limits behave for trigonometric functions as x0x \to 0?
  5. What other methods exist to simplify limits involving trigonometric functions?

Tip: For problems involving trigonometric limits, small-angle approximations are often very useful for quick solutions.

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Math Problem Analysis

Mathematical Concepts

Calculus
Limits
Trigonometric Functions

Formulas

Small-angle approximations: \(\sin x \approx x\), \(\tan x \approx x\)
Limit properties for trigonometric functions: \( \lim_{x \to 0} \frac{\sin x}{x} = 1 \), \( \lim_{x \to 0} \frac{\tan x}{x} = 1 \)

Theorems

Limit properties
Small-angle approximation

Suitable Grade Level

Grades 10-12