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Ch. 2 - Functions and Graphs
Blitzer - College Algebra 8th Edition
Blitzer8th EditionCollege AlgebraISBN: 9780136970514당신이 사용하는 게 아니라요?교과서 변경
3장, 문제 31a

Find ƒ+g and determine the domain for each function. f(x) = 2x + 3, g(x) = x − 1

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Identify the given functions: \(f(x) = 2x + 3\) and \(g(x) = x - 1\).
To find \((f + g)(x)\), add the two functions together: \((f + g)(x) = f(x) + g(x)\).
Substitute the expressions for \(f(x)\) and \(g(x)\) into the sum: \((f + g)(x) = (2x + 3) + (x - 1)\).
Combine like terms to simplify the expression: \((f + g)(x) = 2x + x + 3 - 1\).
Determine the domain of \((f + g)(x)\) by finding the intersection of the domains of \(f(x)\) and \(g(x)\). Since both are linear functions defined for all real numbers, the domain is all real numbers.

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주요 개념

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Function Addition (ƒ + g)

Function addition involves creating a new function by adding the outputs of two given functions for the same input value. For functions f(x) and g(x), (ƒ + g)(x) = f(x) + g(x). This operation combines the expressions algebraically to form a single function.
추천 영상:
4:56
Function Composition

Domain of a Function

The domain of a function is the set of all input values (x-values) for which the function is defined. When combining functions, the domain of the resulting function is the intersection of the domains of the original functions, ensuring all inputs are valid for both.
추천 영상:
3:51
Domain Restrictions of Composed Functions

Linear Functions

Linear functions are polynomial functions of degree one, typically written as f(x) = mx + b. They have a constant rate of change and their graphs are straight lines. Understanding their form helps in performing operations like addition and determining domains easily.
추천 영상:
06:07
Linear Inequalities