Table of contents
- 0. Functions7h 52m
- Introduction to Functions16m
- Piecewise Functions10m
- Properties of Functions9m
- Common Functions1h 8m
- Transformations5m
- Combining Functions27m
- Exponent rules32m
- Exponential Functions28m
- Logarithmic Functions24m
- Properties of Logarithms34m
- Exponential & Logarithmic Equations35m
- Introduction to Trigonometric Functions38m
- Graphs of Trigonometric Functions44m
- Trigonometric Identities47m
- Inverse Trigonometric Functions48m
- 1. Limits and Continuity2h 2m
- 2. Intro to Derivatives1h 33m
- 3. Techniques of Differentiation3h 18m
- 4. Applications of Derivatives2h 38m
- 5. Graphical Applications of Derivatives6h 2m
- 6. Derivatives of Inverse, Exponential, & Logarithmic Functions2h 37m
- 7. Antiderivatives & Indefinite Integrals1h 26m
- 8. Definite Integrals4h 44m
- 9. Graphical Applications of Integrals2h 27m
- 10. Physics Applications of Integrals 2h 22m
3. Techniques of Differentiation
Product and Quotient Rules
Problem 3.23
Textbook Question
Find the derivatives of the functions in Exercises 1–42.
𝔂 = x⁻¹/² sec (2x)²

1
Identify the function components: The given function is 𝔂 = x<sup>-1/2</sup> sec((2x)<sup>2</sup>). This is a product of two functions: u(x) = x<sup>-1/2</sup> and v(x) = sec((2x)<sup>2</sup>).
Apply the product rule: The derivative of a product of two functions u(x) and v(x) is given by (uv)' = u'v + uv'.
Differentiate u(x): The derivative of u(x) = x<sup>-1/2</sup> is u'(x) = -1/2 * x<sup>-3/2</sup>.
Differentiate v(x): To find v'(x), use the chain rule. The derivative of sec(z) is sec(z)tan(z), where z = (2x)<sup>2</sup>. First, find the derivative of z with respect to x, which is dz/dx = 4x. Then, v'(x) = sec((2x)<sup>2</sup>)tan((2x)<sup>2</sup>) * 4x.
Combine the results: Substitute u(x), u'(x), v(x), and v'(x) into the product rule formula to find the derivative of 𝔂. Simplify the expression to obtain the final derivative.

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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Derivative Rules
Understanding the rules of differentiation, such as the product rule, quotient rule, and chain rule, is essential for finding derivatives of complex functions. The product rule is used when differentiating products of functions, while the chain rule is necessary for composite functions. Mastery of these rules allows for systematic and accurate differentiation.
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Trigonometric Functions
The function sec(2x) is a trigonometric function, specifically the secant function, which is the reciprocal of the cosine function. Knowing the derivatives of trigonometric functions, such as sec(x), is crucial for differentiating expressions involving them. The derivative of sec(x) is sec(x)tan(x), which will be applied in this context.
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Power Rule
The power rule is a fundamental concept in calculus that states if f(x) = x^n, then f'(x) = n*x^(n-1). This rule is particularly useful for differentiating functions with exponents, such as x^(-1/2) in the given function. Applying the power rule correctly is vital for simplifying the differentiation process.
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