What are the vertical and horizontal asymptotes of f(x) = x/x+3-2 ?

1 Answer
Apr 20, 2018

See below.

Explanation:

Not quite sure of your notation here. I'm reading this as:

#f(x)=x/(x+3)-2#

Vertical asymptotes occur where the function is undefined.

For:

#x=-3#

#x/(0)-2#

Undefined, division by zero:

Vertical asymptote is the line:

#color(blue)(x=-3)#

We now see what happens as #x->+-oo#

#x/(x+3)-2#

Divide fraction by #x#:

#(x/x)/(x/x+3/x)-2#

Cancelling:

#1/(1+3/x)-2#

as #x->oocolor(white)(88888)# , #1/(1+3/x)-2=1/(1+0)-2=-1#

as #x->-oocolor(white)(88888)# , #1/(1+3/x)-2=1/(1+0)-2=-1#

This shows that as we approach #+-oo#, the function tends to #-1#.

This is a horizontal asymptote:

#color(blue)(y=-1)#

The graph of #f(x)=x/(x+3)-2# confirms this:

enter image source here