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 80
Textbook Question
Derivatives from a table Use the following table to find the given derivatives. <IMAGE>
d/dx (xf(x) / g(x)) |x=4

1
Step 1: Identify the function to differentiate. We have the function \( \frac{x f(x)}{g(x)} \).
Step 2: Apply the quotient rule for derivatives. The quotient rule states that if you have a function \( \frac{u(x)}{v(x)} \), its derivative is \( \frac{u'(x)v(x) - u(x)v'(x)}{(v(x))^2} \). Here, \( u(x) = x f(x) \) and \( v(x) = g(x) \).
Step 3: Differentiate \( u(x) = x f(x) \) using the product rule. The product rule states that \( (uv)' = u'v + uv' \). So, \( u'(x) = 1 \cdot f(x) + x \cdot f'(x) \).
Step 4: Differentiate \( v(x) = g(x) \). The derivative is \( v'(x) = g'(x) \).
Step 5: Substitute \( u'(x) \), \( v(x) \), \( u(x) \), and \( v'(x) \) into the quotient rule formula and evaluate at \( x = 4 \).

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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Product Rule
The Product Rule is a fundamental principle in calculus used to differentiate products of two functions. It states that if you have two functions, u(x) and v(x), the derivative of their product is given by u'v + uv'. This rule is essential for finding the derivative of the function in the question, which involves the product of x and f(x).
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Quotient Rule
The Quotient Rule is another key differentiation rule used when dealing with the division of two functions. If you have a function h(x) = u(x)/v(x), the derivative is given by (u'v - uv')/v^2. This rule is crucial for differentiating the expression xf(x)/g(x) in the question, as it involves both a product and a quotient of functions.
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Evaluating Derivatives at a Point
Evaluating derivatives at a specific point involves substituting the value of x into the derivative function after it has been calculated. In this case, after applying the Product and Quotient Rules, you will substitute x = 4 into the resulting derivative expression to find the specific value of the derivative at that point. This step is essential for obtaining the final answer.
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