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The two functions f and g are inverse functions if and only if both of their compositions are the identity function.
Yes, see solution.
We want to determine whether the given pair of functions are inverse functions. f(x)=3x+8 and g(x)= x-83 To do so, we need to verify that the compositions of f(x) and g(x) are the identity function.
Recall that [f ∘ g](x) = f(g(x)). To find the expression, we will start by substituting x-83 for g(x).
Now we apply the definition of f(x). f(x)=3x+8 ⇓ f( x-8/3) = 3( x-8/3)+8 Finally, let's simplify and see if the function is the identity function.
a*b/c= a* b/c
Calculate quotient
Add terms
We found that [f ∘ g](x) is the identity function.
Similarly, recall that [g ∘ f](x) = g( f(x) ). To find the expression, this time we will start by substituting 3x+8 for f(x).
Now we apply the definition of g(x). g(x)=x-8/3 ⇓ g( 3x+8 ) = ( 3x+8)-8/3 Finally, let's simplify and see if the function is the identity function.
Remove parentheses
Add and subtract terms
Calculate quotient
We found that [g ∘ f](x) is also the identity function. Thus, f(x) and g(x) are inverse functions.