We want to determine whether the given pair of functions are .
f(x)=2x+16 and g(x)= 12x-8
To do so, we need to verify that the compositions of f(x) and g(x) are the .
Calculating [f ∘ g](x)
Recall that [f ∘ g](x) = f(g(x)). To find the expression, we will start by substituting 12x-8 for g(x).
[f ∘ g](x) = f ( g(x) )
[f ∘ g](x) = f ( 1/2x-8 )
Now we apply the definition of f(x).
f(x)=2x+16
⇓
f( 12x-8 ) = 2( 12x-8 ) + 16
Finally, let's simplify and see if the function is the identity function.
[f ∘ g](x) = 2( 1/2x-8) + 16
[f ∘ g](x) = x - 16 + 16
[f ∘ g](x) = x ✓
We found that [f ∘ g](x) is the identity function.
Calculating [g ∘ f](x)
Similarly, recall that [g ∘ f](x) = g( f(x) ). To find the expression, this time we will start by substituting 2x+16 for f(x).
[g ∘ f](x) = g ( f(x) )
[g ∘ f](x) = g ( 2x+16 )
Now we apply the definition of g(x).
g(x)= 12x-8
⇓
g( 2x+16 ) = 12( 2x+16)-8
Finally, let's simplify and see if the function is the
identity function.
[g ∘ f](x) = 1/2(2x+16)-8
[g ∘ f](x) = x+8-8
[g ∘ f](x) = x ✓
We found that [g ∘ f](x) is also the identity function. As such, f(x) and g(x) are inverse functions.