Math Problem Statement

Evaluate the limit \( \lim_{{h \to 0}} \frac{{\sin(x+h) - \sin(x)}}{h} \)

Solution

The given expression represents the derivative of the sine function using its definition as a limit. The expression is:

limh0sin(x+h)sin(x)h\lim_{h \to 0} \frac{\sin(x+h) - \sin(x)}{h}

This is the definition of the derivative of sin(x)\sin(x) at a point xx, using the limit definition of the derivative. To solve this limit, we use the trigonometric identity for the difference of sines:

sin(x+h)sin(x)=2cos(x+h+x2)sin(h2)\sin(x+h) - \sin(x) = 2\cos\left(\frac{x+h+x}{2}\right)\sin\left(\frac{h}{2}\right)

However, instead of using the identity, let's directly differentiate the sine function using basic calculus. The derivative of sin(x)\sin(x) is:

ddx[sin(x)]=cos(x)\frac{d}{dx}[\sin(x)] = \cos(x)

Thus:

limh0sin(x+h)sin(x)h=cos(x)\lim_{h \to 0} \frac{\sin(x+h) - \sin(x)}{h} = \cos(x)

Therefore, the limit simplifies to cos(x)\cos(x).

Would you like more details or have any specific questions?


Here are 5 related questions to consider:

  1. What is the limit definition of the derivative for any general function f(x)f(x)?
  2. How can you use trigonometric identities to simplify limits involving sine and cosine?
  3. What are the derivatives of other common trigonometric functions such as cos(x)\cos(x) and tan(x)\tan(x)?
  4. How does the derivative of a trigonometric function behave graphically?
  5. What are the higher-order derivatives of sin(x)\sin(x) and cos(x)\cos(x)?

Tip: Understanding the limit definition of the derivative is key to mastering calculus, especially for trigonometric functions.

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Math Problem Analysis

Mathematical Concepts

Calculus
Limits
Trigonometry
Derivative of Trigonometric Functions

Formulas

\lim_{{h \to 0}} \frac{{\sin(x+h) - \sin(x)}}{h}
Derivative of \sin(x): \frac{d}{dx}[\sin(x)] = \cos(x)

Theorems

Limit Definition of Derivatives

Suitable Grade Level

Grades 11-12