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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 5

Find f(g(x)) and g (f(x)) and determine whether each pair of functions ƒ and g are inverses of each other. f(x)=5x-9 and g(x) = (x+5)/9

검증된 단계별 안내
1
First, find the composition \( f(g(x)) \) by substituting \( g(x) = \frac{x+5}{9} \) into \( f(x) = 5x - 9 \). This means replacing every \( x \) in \( f(x) \) with \( \frac{x+5}{9} \). So, write \( f\left(g(x)\right) = 5 \left( \frac{x+5}{9} \right) - 9 \).
Next, simplify the expression for \( f(g(x)) \) by distributing the 5 and combining like terms carefully. This will give you a simplified function in terms of \( x \).
Then, find the composition \( g(f(x)) \) by substituting \( f(x) = 5x - 9 \) into \( g(x) = \frac{x+5}{9} \). Replace every \( x \) in \( g(x) \) with \( 5x - 9 \), so write \( g\left(f(x)\right) = \frac{(5x - 9) + 5}{9} \).
Simplify the expression for \( g(f(x)) \) by combining like terms in the numerator and then dividing by 9 to get a simplified function in terms of \( x \).
Finally, determine whether \( f \) and \( g \) are inverses by checking if both compositions \( f(g(x)) \) and \( g(f(x)) \) simplify to \( x \). If both equal \( x \), then \( f \) and \( g \) are inverse functions of each other.

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주요 개념

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

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Algebraic manipulation involves simplifying expressions, solving equations, and substituting variables accurately. Mastery of these skills is essential to correctly compute compositions and verify if two functions are inverses by simplifying the resulting expressions.
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