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 72
Textbook Question
First and second derivatives Find f′(x),f′′(x).
f(x) = x/x+2

1
Step 1: Rewrite the function f(x) = \frac{x}{x+2} in a form suitable for differentiation. This can be done by recognizing it as a quotient of two functions, where the numerator u(x) = x and the denominator v(x) = x + 2.
Step 2: Apply the Quotient Rule for differentiation to find the first derivative f'(x). The Quotient Rule states that if you have a function h(x) = \frac{u(x)}{v(x)}, then h'(x) = \frac{u'(x)v(x) - u(x)v'(x)}{(v(x))^2}.
Step 3: Differentiate the numerator and the denominator separately. For u(x) = x, the derivative u'(x) = 1. For v(x) = x + 2, the derivative v'(x) = 1.
Step 4: Substitute the derivatives u'(x) and v'(x) into the Quotient Rule formula to find f'(x). This gives f'(x) = \frac{1 \cdot (x+2) - x \cdot 1}{(x+2)^2}. Simplify the expression to get the first derivative.
Step 5: To find the second derivative f''(x), differentiate f'(x) with respect to x. This may involve using the Quotient Rule again if f'(x) is still in a quotient form, or using the Power Rule if it simplifies to a polynomial form.

This video solution was recommended by our tutors as helpful for the problem above
Video duration:
7mPlay a video:
Was this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
First Derivative
The first derivative of a function, denoted as f'(x), represents the rate of change of the function with respect to its variable. It provides information about the slope of the tangent line to the curve at any given point. In practical terms, it can indicate whether the function is increasing or decreasing and can help identify critical points where the function may have local maxima or minima.
Recommended video:
The First Derivative Test: Finding Local Extrema
Second Derivative
The second derivative, denoted as f''(x), is the derivative of the first derivative. It measures the rate of change of the first derivative, providing insights into the concavity of the function. A positive second derivative indicates that the function is concave up (shaped like a cup), while a negative second derivative indicates concave down (shaped like a cap). This information is crucial for understanding the behavior of the function and identifying points of inflection.
Recommended video:
The Second Derivative Test: Finding Local Extrema
Quotient Rule
The quotient rule is a method for finding the derivative of a function that is the ratio of two other functions. If f(x) = g(x)/h(x), the derivative is given by f'(x) = (g'(x)h(x) - g(x)h'(x)) / (h(x))^2. This rule is essential when differentiating functions like f(x) = x/(x+2), as it allows for the correct application of calculus to find both the first and second derivatives.
Recommended video:
The Quotient Rule
Related Videos
Related Practice