Math Problem Statement

evaluate the limit as x approaches 0 of (sin3x)/x

Solution

To evaluate the limit limx0sin(3x)x\lim_{x \to 0} \frac{\sin(3x)}{x}, we can use the standard trigonometric limit:

limx0sin(x)x=1.\lim_{x \to 0} \frac{\sin(x)}{x} = 1.

We will manipulate the expression to use this standard limit.

Rewrite the expression by introducing a factor of 3 in the denominator:

limx0sin(3x)x=limx0sin(3x)3x3.\lim_{x \to 0} \frac{\sin(3x)}{x} = \lim_{x \to 0} \frac{\sin(3x)}{3x} \cdot 3.

Now, notice that the limit inside the product can be recognized as a form of the standard trigonometric limit:

limx0sin(3x)3x=1.\lim_{x \to 0} \frac{\sin(3x)}{3x} = 1.

Thus, we can evaluate the original limit as follows:

limx0sin(3x)x=(limx0sin(3x)3x)3=13=3.\lim_{x \to 0} \frac{\sin(3x)}{x} = \left( \lim_{x \to 0} \frac{\sin(3x)}{3x} \right) \cdot 3 = 1 \cdot 3 = 3.

Therefore, the limit is:

limx0sin(3x)x=3.\lim_{x \to 0} \frac{\sin(3x)}{x} = 3.

Would you like further details or have any questions?

Here are 5 related questions that expand on this topic:

  1. How would you evaluate limx0sin(5x)x\lim_{x \to 0} \frac{\sin(5x)}{x}?
  2. What is the limit limx0sin(x)sin(2x)\lim_{x \to 0} \frac{\sin(x)}{\sin(2x)}?
  3. How can L'Hopital's rule be applied to solve limits involving trigonometric functions?
  4. Why is the standard limit limx0sin(x)x=1\lim_{x \to 0} \frac{\sin(x)}{x} = 1 important in calculus?
  5. How would you find limx0tan(2x)x\lim_{x \to 0} \frac{\tan(2x)}{x}?

Tip: Whenever evaluating limits involving trigonometric functions, see if you can rewrite them to use standard limits like limx0sin(x)x=1\lim_{x \to 0} \frac{\sin(x)}{x} = 1.

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Math Problem Analysis

Mathematical Concepts

Limits
Trigonometric Functions

Formulas

Standard limit: \(\lim_{x \to 0} \frac{\sin(x)}{x} = 1\)

Theorems

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Suitable Grade Level

Advanced High School