What are the vertical asymptotes and holes for the graph of #y=((x-5)(x-2))/((x-2)(x+4)#?

2 Answers
Nov 23, 2016

# x=-4 => # vertical asymptote
# x=2 => # removable discontinuity

Explanation:

# y= ((x-5)(x-2))/((x-2)(x+4)) #

Look at the denominator and determine the values for which it is zero:

# (x-2)(x+4) = 0=> x=2, -4 #

There is a common factor of (x-2), so we can cancel that common factor:

# y= ((x-5)cancel(x-2))/(cancel(x-2)(x+4)) #

But note we can only do that provided #x-2!=0#, ie #x!=2#

We have already established that when #x=2# the denominator is zero, so there is a removable discontinuity at that point (or a "hole")

When #x=-4# the denominator is also zero and this is the only vertical asymptote.

graph{((x-5)(x-2))/((x-2)(x+4)) [-21.08, 18.92, -9.52, 10.48]}

Nov 23, 2016

The vertical asymptote : #x = -4#
The horizontal asymptote: y = 1.

Explanation:

By actual division and rearrangement,

#(y-1)(x+4)=-9#

This represents the rectangular hyperbola (RH), with the

perpendicular asymptotes #y-1=0 and x+4=0 and#

center at #(-4, 1)#.

The graph of the RH is already included, in another answer. .