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 3.4.15
Textbook Question
Given that f(1) = 5, f′(1) = 4, g(1) = 2, and g′(1) = 3 , find d/dx (f(x)g(x))∣ ∣x=1 and d/dx (f(x) / g(x)) ∣ x=1.

1
Step 1: To find the derivative of the product of two functions, use the product rule. The product rule states that if you have two functions f(x) and g(x), then the derivative of their product is given by: (f(x)g(x))' = f'(x)g(x) + f(x)g'(x).
Step 2: Apply the product rule to the given functions at x = 1. Substitute f(1) = 5, f'(1) = 4, g(1) = 2, and g'(1) = 3 into the product rule formula: (f(x)g(x))'|_{x=1} = f'(1)g(1) + f(1)g'(1).
Step 3: To find the derivative of the quotient of two functions, use the quotient rule. The quotient rule states that if you have two functions f(x) and g(x), then the derivative of their quotient is given by: (f(x)/g(x))' = (f'(x)g(x) - f(x)g'(x)) / (g(x))^2.
Step 4: Apply the quotient rule to the given functions at x = 1. Substitute f(1) = 5, f'(1) = 4, g(1) = 2, and g'(1) = 3 into the quotient rule formula: (f(x)/g(x))'|_{x=1} = (f'(1)g(1) - f(1)g'(1)) / (g(1))^2.
Step 5: Simplify the expressions obtained from the product and quotient rules to find the derivatives at x = 1.

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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 the product of two functions. It states that if you have two functions, f(x) and g(x), the derivative of their product is given by f'(x)g(x) + f(x)g'(x). This rule is essential for solving the first part of the question, where we need to find the derivative of the product f(x)g(x) at x=1.
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Quotient Rule
The Quotient Rule is another important differentiation rule that applies when dividing two functions. It states that if you have a function h(x) = f(x)/g(x), the derivative is given by (f'(x)g(x) - f(x)g'(x)) / (g(x))^2. This rule is crucial for solving the second part of the question, where we need to find the derivative of the quotient f(x)/g(x) at x=1.
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Evaluation of Derivatives
Evaluating derivatives at a specific point involves substituting the value of x into the derivative expression after applying the appropriate differentiation rules. In this question, we will substitute x=1 into the results obtained from the Product and Quotient Rules to find the specific values of the derivatives at that point, which is necessary for completing the problem.
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