Question #c347b

2 Answers
Nov 8, 2017

The line #y=1# is a horizontal asymptote.
The line #x=3# is a vertical asymptote.

Explanation:

Note first that we can simplify the function:

#f(x) = (x^2-9)/(x^2+6x+9) = ((x-3)(x+3))/(x+3)^2 = (x-3)/(x+3)#

Now we have:

#lim_(x->oo) f(x) = lim_(x->-oo) f(x)= 1#

so the line #y=1# is a horizontal asymptote.

The function #f(x)# is continuous for every #x in RR# except for #x=3#, where we have:

# lim_(x->3^-) f(x) = -oo#

# lim_(x->3^+) f(x) = +oo#

Thus the line #x=3# is a vertical asymptote.

graph{(x^2-9)/(x^2+6x+9) [-73, 73, -36.5, 36.5]}

Nov 8, 2017

vertical

Explanation:

this equation can be simplified:

#f(x) = (x^2-9)/(x^2+6x+9)#

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

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

#f(x) = (x-3)/(x+3), x!= -3#

since it is a value of #x# being restricted, the asymptote of this graph is vertical.

graph{(x-3)/(x+3) [-13.5, 6.5, -5.88, 4.12]}