For the pair of functions defined, find (ƒ+g)(x), (ƒ-g)(x), (ƒg)(x), and (f/g)(x).Give the domain of each. ƒ(x)=4x2+2x, g(x)=x2-3x+2
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 18
Textbook Question
Let ƒ(x)=x^2+3 and g(x)=-2x+6. Find each of the following. See Example 1.
(ƒ/g)(5)
Verified step by step guidance1
Understand that the notation (ƒ/g)(5) means the value of the function ƒ(x) divided by g(x) evaluated at x = 5, which can be written as \( \frac{ƒ(5)}{g(5)} \).
Calculate \( ƒ(5) \) by substituting 5 into the function ƒ(x) = \( x^2 + 3 \). This gives \( ƒ(5) = 5^2 + 3 \).
Calculate \( g(5) \) by substituting 5 into the function g(x) = \( -2x + 6 \). This gives \( g(5) = -2(5) + 6 \).
Form the quotient \( \frac{ƒ(5)}{g(5)} \) by dividing the result from step 2 by the result from step 3.
Simplify the expression from step 4 to find the final value of \( (ƒ/g)(5) \).
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Function Notation and Evaluation
Function notation, such as ƒ(x), represents a rule that assigns each input x to an output value. Evaluating a function at a specific value means substituting that value into the function's expression and simplifying to find the output.
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Evaluating Composed Functions
Function Division (Quotient of Functions)
The division of two functions (ƒ/g)(x) is defined as the quotient of their outputs: ƒ(x) divided by g(x). To find (ƒ/g)(5), evaluate both ƒ(5) and g(5) separately, then divide the results, ensuring the denominator is not zero.
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Multiplying & Dividing Functions
Polynomial and Linear Functions
ƒ(x) = x² + 3 is a polynomial function of degree 2, and g(x) = -2x + 6 is a linear function. Understanding their forms helps in correctly substituting values and simplifying expressions during evaluation.
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Introduction to Polynomial Functions
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