Answer
See proofs
Work Step by Step
We are given the functions:
$f(x)=x-5$
$g(x)=x+5$
a) Verify that the two functions are inverse functions.
Determine $f\circ g$ and $g\circ f$:
$(f\circ g)(x)=f(g(x))=f(x+5)=x+5-5=x$
$(g\circ f)(x)=g(f(x))=g(x-5)=x-5+5=x$
We got:
$(f\circ g)(x)=(g\circ f)(x)=x$,
therefore the two functions are inverse functions.
b) Graph $f$ and $g$ and the line $y=x$.
As the graphs of $f$ and $g$ are symmetric with respect to the line $y=x$, $f$ and $g$ are inverse functions.