Skip to main content
Ch. 2 - Functions and Graphs
Blitzer - College Algebra 8th Edition
Blitzer8th EditionCollege AlgebraISBN: 9780136970514당신이 사용하는 게 아니라요?교과서 변경
3장, 문제 71

Find a. (fog) (x) b. the domain of f o g.
f(x) = √x, g(x) = x − 2

검증된 단계별 안내
1
Step 1: Understand the composition of functions. The notation (fog)(x) represents the composition of f and g, which means f(g(x)). To find this, substitute g(x) into f(x).
Step 2: Substitute g(x) = x − 2 into f(x) = √x. This gives f(g(x)) = √(x − 2).
Step 3: Analyze the domain of the composition f(g(x)). Since f(x) = √x involves a square root, the expression inside the square root must be non-negative. Therefore, x − 2 ≥ 0.
Step 4: Solve the inequality x − 2 ≥ 0 to find the domain. Add 2 to both sides to get x ≥ 2.
Step 5: Conclude that the domain of f o g is all x-values such that x ≥ 2. In interval notation, this is [2, ∞).

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
2m

주요 개념

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

Function Composition

Function composition involves combining two functions, where the output of one function becomes the input of another. In this case, (f o g)(x) means applying g first and then applying f to the result of g. Understanding how to correctly perform this operation is essential for solving the problem.
추천 영상:
가이드 코스
4:56
Function Composition

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. For the composition of functions, the domain of f o g is determined by the values that g can take and the values that f can accept. Identifying these domains is crucial for ensuring that the composed function is valid.
추천 영상:
가이드 코스
3:51
Domain Restrictions of Composed Functions

Square Root Function

The square root function, denoted as f(x) = √x, is defined only for non-negative values of x. This means that for f to be valid, the input must be greater than or equal to zero. Understanding the restrictions imposed by the square root function is vital for determining the overall domain of the composed function f o g.
추천 영상:
가이드 코스
02:20
Imaginary Roots with the Square Root Property