Skip to main content
Ch. 2 - Graphs and Functions
Lial - College Algebra 13th Edition
Lial13th EditionCollege AlgebraISBN: 9780136881063당신이 사용하는 게 아니라요?교과서 변경
3장, 문제 87b

Given functions f and g, (g∘ƒ)(x) and its domain. ƒ(x)=1/(x-2), g(x)=1/x

검증된 단계별 안내
1
Identify the composition of functions (g \(\circ\) f)(x), which means g(f(x)). This involves substituting the entire function f(x) into g(x).
Write down the given functions explicitly: \( f(x) = \frac{1}{x-2} \) and \( g(x) = \frac{1}{x} \).
Substitute \( f(x) \) into \( g(x) \) to get \( (g \circ f)(x) = g\left( \frac{1}{x-2} \right) = \frac{1}{\frac{1}{x-2}} \).
Simplify the expression \( \frac{1}{\frac{1}{x-2}} \) by multiplying numerator and denominator appropriately to find the simplified form of \( (g \circ f)(x) \).
Determine the domain of \( (g \circ f)(x) \) by considering the restrictions from both \( f(x) \) and \( g(x) \): exclude values where \( x-2=0 \) (to avoid division by zero in \( f(x) \)) and where \( f(x) = 0 \) (to avoid division by zero in \( g(f(x)) \)).

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
4m
도움이 되었나요?

주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Function Composition

Function composition involves applying one function to the result of another, denoted as (g∘f)(x) = g(f(x)). It requires substituting the entire output of f(x) into g, creating a new function that combines both operations.
추천 영상:
4:56
Function Composition

Domain of a Function

The domain of a function is the set of all input values for which the function is defined. When composing functions, the domain of (g∘f)(x) includes all x-values in the domain of f for which f(x) is in the domain of g.
추천 영상:
3:51
Domain Restrictions of Composed Functions

Restrictions from Rational Functions

Rational functions like f(x) = 1/(x-2) and g(x) = 1/x have restrictions where denominators cannot be zero. Identifying these values is essential to determine the domain and ensure the function is defined.
추천 영상:
05:21
Restrictions on Rational Equations