Fundamental Properties of Differentiation

Michael Green
6 min read
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Study Guide Overview
This study guide covers derivatives of sine and cosine functions, including sin(x), cos(x), sin(kx), and cos(kx). It explains differentiation rules and the chain rule, provides worked examples, and offers practice questions. The guide also demonstrates deriving these derivatives using the formal definition of a derivative and includes a glossary of key terms.
#Derivatives of Sine and Cosine Functions
#Table of Contents
- Introduction
- Differentiating Sin x and Cos x
- Differentiating Sin kx and Cos kx
- Worked Examples
- Using the Definition of a Derivative
- Glossary
- Practice Questions
- Summary and Key Takeaways
#Introduction
In calculus, understanding how to differentiate sine and cosine functions is fundamental. This guide covers the rules for differentiating these trigonometric functions, including their more complex forms, and provides worked examples and practice questions to help solidify your understanding.
#Differentiating Sin x and Cos x
#Key Concepts
- If ,
then
- If ,
then
- If ,
then
- If ,
then
- This sequence then repeats.
#Differentiating Sin kx and Cos kx
When dealing with functions of the form and , the differentiation involves the chain rule.
#Key Concepts
- If ,
then
- If ,
then
Remember that these results come from applying the chain rule.
#Worked Examples
#Example 1
Differentiate the following function:
Solution:
differentiates to
differentiates to
So,
#Example 2
Differentiate the following function:
Solution:
differentiates to
differentiates to
So,
Simplifying,
#Using the Definition of a Derivative
#Definition
The derivative of a function can be defined as:
#Differentiating Using the Definition
Given :
Using the addition formula:
So,
Factorizing:
Applying the limits: and
So,
#Differentiating Using the Definition
Given :
Using the addition formula:
So,
Factorizing:
Applying the limits: and
So,
#Glossary
- Derivative: A measure of how a function changes as its input changes.
- Chain Rule: A formula to compute the derivative of a composite function.
- Trigonometric Addition Formulae: Formulas that express trigonometric functions of sums of angles in terms of products of trigonometric functions of individual angles.
- Limit: The value that a function approaches as the input approaches some value.
#Practice Questions
Practice Question
-
Differentiate .
-
Differentiate .
-
Use the definition of a derivative to differentiate .
#Summary and Key Takeaways
- The derivative of is .
- The derivative of is .
- Using the chain rule, the derivatives of and are and , respectively.
- Understanding and applying the definition of a derivative is crucial for deriving these results.
#Key Takeaways
The derivative of is .
The derivative of is .
Use the chain rule for functions involving constants, such as and .
Master the trigonometric addition formulae and limit theorems for deeper understanding.
Practice differentiating using both rules and definitions to solidify understanding.
Always double-check your differentiation, especially the signs when differentiating trigonometric functions.
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