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Ch. 2 - Functions and Graphs
Blitzer - College Algebra 8th Edition
Blitzer8th EditionCollege AlgebraISBN: 9780136970514Non è quello che usi tu?Cambia libro di testo
Capitolo 3, Problema 3

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)=3x+8 and g(x) = (x-8)/3

Guida verificata passo dopo passo
1
First, find the composition \( f(g(x)) \) by substituting \( g(x) \) into \( f(x) \). This means replacing every \( x \) in \( f(x) = 3x + 8 \) with \( g(x) = \frac{x - 8}{3} \). So, write \( f(g(x)) = 3 \left( \frac{x - 8}{3} \right) + 8 \).
Next, simplify the expression for \( f(g(x)) \) by performing the multiplication and addition inside the function. Multiply 3 by \( \frac{x - 8}{3} \) and then add 8.
Then, find the composition \( g(f(x)) \) by substituting \( f(x) \) into \( g(x) \). Replace every \( x \) in \( g(x) = \frac{x - 8}{3} \) with \( f(x) = 3x + 8 \). So, write \( g(f(x)) = \frac{(3x + 8) - 8}{3} \).
Simplify the expression for \( g(f(x)) \) by performing the subtraction in the numerator and then dividing by 3.
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.

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Inverse Functions

Inverse functions reverse the effect of each other, meaning f(g(x)) = x and g(f(x)) = x for all x in the domain. To verify if two functions are inverses, we check if their compositions yield the identity function, which returns the input unchanged.
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Algebraic Manipulation

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