Questions: Find f(g(x)) and g(f(x)) and determine whether the pair of functions f and g are inverses of each other.
f(x)=9x+5 and g(x)=(x-5)/9
a. f(g(x))= (Simplify your answer.)
Transcript text: Find $\mathrm{f}(\mathrm{g}(\mathrm{x}))$ and $\mathrm{g}(\mathrm{f}(\mathrm{x}))$ and determine whether the pair of functions f and g are inverses of each other.
\[
f(x)=9 x+5 \text { and } g(x)=\frac{x-5}{9}
\]
a. $f(g(x))=$ $\square$ (Simplify your answer.)
Solution
Solution Steps
To determine if two functions \( f \) and \( g \) are inverses of each other, we need to check if \( f(g(x)) = x \) and \( g(f(x)) = x \). We will first compute \( f(g(x)) \) by substituting \( g(x) \) into \( f(x) \) and simplifying the expression.
Step 1: Calculate \( f(g(x)) \)
We start by substituting \( g(x) \) into \( f(x) \). Given the functions:
\[
f(x) = 9x + 5 \quad \text{and} \quad g(x) = \frac{x - 5}{9}
\]
we compute \( f(g(x)) \):
\[
f(g(x)) = f\left(\frac{x - 5}{9}\right) = 9\left(\frac{x - 5}{9}\right) + 5
\]
Simplifying this expression:
\[
f(g(x)) = (x - 5) + 5 = x
\]
Step 2: Calculate \( g(f(x)) \)
Next, we compute \( g(f(x)) \) by substituting \( f(x) \) into \( g(x) \):
\[
g(f(x)) = g(9x + 5) = \frac{(9x + 5) - 5}{9}
\]
Simplifying this expression:
\[
g(f(x)) = \frac{9x}{9} = x
\]
Step 3: Determine if \( f \) and \( g \) are inverses
Since we have found that:
\[
f(g(x)) = x \quad \text{and} \quad g(f(x)) = x
\]
this confirms that the functions \( f \) and \( g \) are indeed inverses of each other.
Final Answer
The functions \( f \) and \( g \) are inverses of each other, and we have:
\[
\boxed{f(g(x)) = x \text{ and } g(f(x)) = x}
\]