Questions: For the given functions f and g , find the indicated composition.
f(x)=(x-6)/2, g(x)=2x+6 ;(g∘f)(x)
A. 2x+6
B. x-3
C. x+12
D. x
Transcript text: For the given functions f and g , find the indicated composition.
\[
f(x)=\frac{x-6}{2}, g(x)=2 x+6 ;(g \circ f)(x)
\]
A. $2 x+6$
B. $x-3$
C. $x+12$
D. x
Solution
Solution Steps
To find the composition \((g \circ f)(x)\), we need to substitute the function \(f(x)\) into the function \(g(x)\). This means we will replace every instance of \(x\) in \(g(x)\) with \(f(x)\). After substitution, simplify the expression to find the resulting function.
Step 1: Define the Functions
We have the functions defined as follows:
\[
f(x) = \frac{x - 6}{2}
\]
\[
g(x) = 2x + 6
\]
Step 2: Compute the Composition
To find \((g \circ f)(x)\), we substitute \(f(x)\) into \(g(x)\):
\[
g(f(x)) = g\left(\frac{x - 6}{2}\right)
\]
Substituting \(f(x)\) into \(g(x)\):
\[
g\left(\frac{x - 6}{2}\right) = 2\left(\frac{x - 6}{2}\right) + 6
\]
Step 3: Simplify the Expression
Now, we simplify the expression:
\[
= (x - 6) + 6 = x
\]
Final Answer
Thus, the composition \((g \circ f)(x)\) simplifies to:
\[
\boxed{x}
\]