How do you state the domain and range of f(x)=x/(x-1)?

1 Answer
Nov 30, 2016

The domain is x in ] -oo,1 [ uu ] 1,+oo[

The range is f(x) in ] -oo,1 [ uu ] 1,+oo [

Explanation:

As you cannot divide by 0, x!=1

So the domain is x in ] -oo,1 [ uu ] 1,+oo[

For the limits x->+-oo, we take the terms of highest degree in the numerator and the deniminator

lim_(x->+-oo)f(x)=lim_(x->+-oo)x/x=1

lim_(x->1^(-))f(x)=1/0^(-)=-oo

lim_(x->1^(+))f(x)=1/0^(+)=+oo

So the range is f(x) in ] -oo,1 [ uu ] 1,+oo [

graph{x/(x-1) [-10, 10, -5, 4.995]}