Here we need to find fog and gof, and they must be equal to x .
Let's check out fog
fog = f(g(x))
![f((4x+1)/(x))](https://img.qammunity.org/2019/formulas/mathematics/middle-school/z7e5av14su8ppqflxyke9uvex259rnrgjv.png)
Substituting the value of g(x) in f(x) for x, we will get
![(1)/((4x+1)/(x)-4) =(1)/((4x+1-4x)/(x))=x](https://img.qammunity.org/2019/formulas/mathematics/middle-school/71g90o73y8ccbgxfxbgt7iflt1xsxlopkn.png)
Domain
Here the input function is g(x), and the denominator should not be 0. So x should not be zero. Therefore, domain is
![(-\infty,0)U(0, \infty)](https://img.qammunity.org/2019/formulas/mathematics/middle-school/w0oglxwd9frl7evuw9gjxw6lg3zfmr7p30.png)
Now let's check gof
gof = g(f(x))
Here we need to insert f(x) in g(x) for x, and on doing that , we will get
![(4((1)/(x-4))+1)/((1)/(x-4)) = (4+x-4)/(1)=x](https://img.qammunity.org/2019/formulas/mathematics/middle-school/no8uy9hxklch2atof5uird2gtqxkzjhjoz.png)
Domain
Here the input function is f(x), and denominator should not be zero.
SO domain is
![(- \infty,4)U(4, \infty)](https://img.qammunity.org/2019/formulas/mathematics/middle-school/71w2wd7vhf0jlosglq4t5iu4ppc5yg0goc.png)
Since fog = gof =x, so the given function are inverses of each other .