color(blue)("Hole - undefined")
Hole is where the denominator becomes 0. The function becomes undefined at that point. So for this condition we have x=4
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Lets consider the behaviour close to x=4
color(blue)("Vertical Asymptot "->+oo)
If x=4+delta4 where delta4>0 and very small then we have
(4+delta4-2)/(cancel(4)+delta4-cancel(4)) ->2/(delta4)+1
lim_(delta4->color(white)()^+ 0)2/(delta4)+1 color(white)("dd")->color(white)("dd")kcolor(white)("dd")->color(white)("dd")+oo+1=+oo
color(blue)("Vertical Asymptot "->-oo)
If x=4-delta4 where delta4>0 and very small then we have
(4-delta4-2)/(cancel(4)-delta4-cancel(4)) ->(2-delta4)/(-delta4)=-2/(delta4)+1
lim_(delta4->color(white)()^+ 0)-2/(delta4)+1color(white)("dd") ->color(white)("dd")kcolor(white)("dd")->color(white)("dd")-oo+1=-oo
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
color(blue)("Horizontal Asymptot "->+oo)
(x-2)/(x-4)
As x>0 becomes increasing greater and greater the influences of the -2 and -4 become less and less significant. This continues until we have
lim_(x->+oo) (x-2)/(x-4)color(white)("dd")->color(white)("dd")kcolor(white)("dd") ->color(white)("dd")oo/oo=+1
As x<0 becomes increasing less and less the influences of the -2 and -4 become less and less significant. This continues until we have
lim_(x->-oo) (x-2)/(x-4)color(white)("dd")->color(white)("dd")kcolor(white)("dd") ->color(white)("dd")(-oo)/(-oo)=+1