Table of contents
- 0. Review of Algebra4h 18m
- 1. Equations & Inequalities3h 18m
- 2. Graphs of Equations1h 43m
- 3. Functions2h 17m
- 4. Polynomial Functions1h 44m
- 5. Rational Functions1h 23m
- 6. Exponential & Logarithmic Functions2h 28m
- 7. Systems of Equations & Matrices4h 5m
- 8. Conic Sections2h 23m
- 9. Sequences, Series, & Induction1h 22m
- 10. Combinatorics & Probability1h 45m
3. Functions
Function Composition
Problem 22
Textbook Question
For the pair of functions defined, find (ƒ+g)(x), (ƒ-g)(x), (ƒg)(x), and (f/g)(x).Give the domain of each. See Example 2. ƒ(x)=4x^2+2x, g(x)=x^2-3x+2
Verified step by step guidance1
Step 1: To find \((f+g)(x)\), add the functions \(f(x)\) and \(g(x)\). This means combining like terms from \(f(x) = 4x^2 + 2x\) and \(g(x) = x^2 - 3x + 2\).
Step 2: To find \((f-g)(x)\), subtract \(g(x)\) from \(f(x)\). Distribute the negative sign through \(g(x)\) and then combine like terms.
Step 3: To find \((fg)(x)\), multiply \(f(x)\) and \(g(x)\) together. Use the distributive property to expand the product \((4x^2 + 2x)(x^2 - 3x + 2)\).
Step 4: To find \((f/g)(x)\), divide \(f(x)\) by \(g(x)\). Write it as a fraction \(\frac{4x^2 + 2x}{x^2 - 3x + 2}\) and simplify if possible.
Step 5: Determine the domain for each function. For \((f+g)(x)\), \((f-g)(x)\), and \((fg)(x)\), the domain is all real numbers. For \((f/g)(x)\), exclude values that make the denominator zero by solving \(x^2 - 3x + 2 = 0\).
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Function Operations
Function operations involve combining two functions through addition, subtraction, multiplication, and division. For two functions ƒ(x) and g(x), the operations are defined as (ƒ+g)(x) = ƒ(x) + g(x), (ƒ-g)(x) = ƒ(x) - g(x), (ƒg)(x) = ƒ(x) * g(x), and (f/g)(x) = ƒ(x) / g(x). Understanding these operations is essential for manipulating and analyzing functions.
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Multiplying & Dividing Functions
Domain of a Function
The domain of a function is the set of all possible input values (x-values) for which the function is defined. When performing operations on functions, the domain may change, especially in division, where the denominator cannot be zero. Identifying the domain for each resulting function is crucial to ensure valid outputs.
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Domain Restrictions of Composed Functions
Polynomial Functions
Polynomial functions are expressions that involve variables raised to whole number powers, combined using addition, subtraction, and multiplication. In this question, both ƒ(x) and g(x) are polynomials. Understanding their structure helps in performing operations and analyzing their behavior, such as finding roots and determining the domain.
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Introduction to Polynomial Functions
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Related Practice
Textbook Question
For the pair of functions defined, find (ƒ+g)(x), (ƒ-g)(x), (ƒg)(x), and (f/g)(x).Give the domain of each. See Example 2. ƒ(x)=√(5x-4), g(x)=-(1/x)
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