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

1 Answer
Jul 9, 2018

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

Explanation:

Perform a long divoision

#color(white)(aaaa)##x^2-5x+6##color(white)(aaaa)##|##x-4#

#color(white)(aaaa)##x^2-4x##color(white)(aaaaaaa)##|##x-1#

#color(white)(aaaaa)##0-x+6#

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

#color(white)(aaaaaaaaa)##0+2#

Therefore,

#f(x)=(x^2-5x+6)/(x-4)=(x-1)+2/(x-4)#

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]}