What is the equation of the oblique asymptote f(x) = (x^2-5x+6)/(x-4)f(x)=x25x+6x4?

1 Answer
Jul 9, 2018

The equation of the asymptote is y=x-1y=x1

Explanation:

Perform a long divoision

color(white)(aaaa)aaaax^2-5x+6x25x+6color(white)(aaaa)aaaa|x-4x4

color(white)(aaaa)aaaax^2-4xx24xcolor(white)(aaaaaaa)aaaaaaa|x-1x1

color(white)(aaaaa)aaaaa0-x+60x+6

color(white)(aaaaaaa)aaaaaaa-x+4x+4

color(white)(aaaaaaaaa)aaaaaaaaa0+20+2

Therefore,

f(x)=(x^2-5x+6)/(x-4)=(x-1)+2/(x-4)f(x)=x25x+6x4=(x1)+2x4

To determine the slant asymptotes, determine the limits

lim_(x->+oo)( f(x)-(x-1))=lim_(x->+oo)2/(x-4)=0^+

The curve is above the asymptote

lim_(x->-oo)( f(x)-(x-1))=lim_(x->-oo)2/(x-4)=0^-

The curve is below the asymptote

The equation of the asymptote is y=x-1

graph{(y-(x^2-5x+6)/(x-4))(y-x+1)=0 [-23.34, 22.27, -8.58, 14.23]}