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
0. Functions
Combining Functions
Problem 1.1.99
Textbook Question
Simplify the difference quotients ƒ(x+h) - ƒ(x) / h and ƒ(x) - ƒ(a) / (x-a) by rationalizing the numerator.
ƒ(x) = - (3/√x)

1
Step 1: Identify the function f(x) = -\frac{3}{\sqrt{x}} and the expressions to simplify: \frac{f(x+h) - f(x)}{h} and \frac{f(x) - f(a)}{x-a}.
Step 2: For the first expression \frac{f(x+h) - f(x)}{h}, substitute f(x+h) = -\frac{3}{\sqrt{x+h}} and f(x) = -\frac{3}{\sqrt{x}} into the expression.
Step 3: Simplify the numerator of \frac{-\frac{3}{\sqrt{x+h}} + \frac{3}{\sqrt{x}}}{h} by finding a common denominator, which is \sqrt{x+h}\sqrt{x}.
Step 4: Rationalize the numerator by multiplying both the numerator and the denominator by the conjugate of the numerator, which is \sqrt{x+h}\sqrt{x}.
Step 5: For the second expression \frac{f(x) - f(a)}{x-a}, substitute f(x) = -\frac{3}{\sqrt{x}} and f(a) = -\frac{3}{\sqrt{a}}, and rationalize the numerator by multiplying by the conjugate \sqrt{x}\sqrt{a}.

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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Difference Quotient
The difference quotient is a fundamental concept in calculus that represents the average rate of change of a function over an interval. It is defined as the ratio of the change in the function's value to the change in the input value, typically expressed as (ƒ(x+h) - ƒ(x)) / h. This concept is crucial for understanding derivatives, as the limit of the difference quotient as h approaches zero gives the derivative of the function.
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Rationalizing the Numerator
Rationalizing the numerator is a technique used in algebra to eliminate radicals from the numerator of a fraction. This is often done by multiplying the numerator and the denominator by the conjugate of the numerator. In the context of difference quotients, rationalizing helps simplify expressions, making it easier to evaluate limits or perform further calculations.
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Finding Limits Numerically and Graphically
Function Evaluation
Function evaluation involves substituting a specific value into a function to determine its output. In this case, the function ƒ(x) = - (3/√x) requires careful handling of the variable x, especially when simplifying expressions involving h or a. Understanding how to evaluate functions accurately is essential for manipulating difference quotients and applying calculus concepts effectively.
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