graph{3x/((x-2)(x+5)) [-32.46, 32.48, -16.24, 16.22]}
For the domain we need to solve the inequalities #(x-2)(x+5)>0# and #(x-2)(x+5)<0#
Since we can't have a zero in the denominator.
#(x-2)(x+5)>0=> x>2 , x<-5#
#(x-2)(x+5)<0=> x> -5 , x < 2#
This gives:
#{x in RR : -oo < x < -5}uu{x in RR : -5 < x < 2}uu{x in RR : 2 < x < oo}#
This could also be expressed:
#{x in RR : x != 2 and x != -5 }#
#y# axis intercepts occur where #x = 0#
#(3(0))/((0-2)(0+5))=0#
Vertical asymptotes occur when the denominator is 0, this is at #x=2# and #x=-5#
Equations of these are:
#x=2# and #x=-5#
As #x# increases without bound in the positive direction:
#x-> oo# , #(3x)/((x-2)(x+5)) -> 0#
And in the negative direction:
#x-> -oo# , #(3x)/((x-2)(x+5)) -> 0#
So:
#y=0# is a horizontal asymptote.