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Ch. 2 - Graphs and Functions
Lial - College Algebra 13th Edition
Lial13th EditionCollege AlgebraISBN: 9780136881063당신이 사용하는 게 아니라요?교과서 변경
3장, 문제 16

Let ƒ(x)=x2+3ƒ(x)=x^2+3 and g(x)=2x+6g(x)=-2x+6. Find each of the following. See Example 1.
(ƒg)(3) (ƒg)(-3)

검증된 단계별 안내
1
Understand that (ƒg)(x) means the composition of functions ƒ and g, which is ƒ(g(x)). This means you first apply g to x, then apply ƒ to the result.
Start by finding g(-3) by substituting -3 into the function g(x) = -2x + 6. Write the expression: \(g(-3) = -2(-3) + 6\).
Simplify the expression for g(-3) to find the value that will be input into ƒ. This involves multiplying and adding the numbers inside the parentheses.
Next, substitute the value found for g(-3) into the function ƒ(x) = x^2 + 3. Write the expression: \(ƒ(g(-3)) = (g(-3))^2 + 3\).
Finally, simplify the expression by squaring the value of g(-3) and then adding 3 to find the value of (ƒg)(-3).

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 applying one function to the result of another, denoted as (ƒg)(x) = ƒ(g(x)). It means you first evaluate g at x, then use that output as the input for ƒ. This concept is essential for understanding how to combine functions and evaluate them at specific values.
추천 영상:
4:56
Function Composition

Evaluating Functions at a Given Input

Evaluating a function at a given input means substituting the input value into the function's formula and simplifying to find the output. For example, to find g(-3), replace x with -3 in g(x) = -2x + 6 and simplify. This step is crucial before composing functions.
추천 영상:
4:26
Evaluating Composed Functions

Polynomial and Linear Functions

ƒ(x) = x² + 3 is a polynomial function, and g(x) = -2x + 6 is a linear function. Understanding their forms helps in correctly substituting and simplifying expressions during evaluation and composition. Recognizing these types aids in anticipating the behavior and complexity of the functions.
추천 영상:
06:04
Introduction to Polynomial Functions