What are the asymptote(s) and hole(s) of # f(x) = (2x-4)/(x^2-3x+2)#?
1 Answer
Explanation:
#"The first step is to factorise and simplify f(x)"#
#f(x)=(2cancel((x-2)))/((x-1)cancel((x-2)))=2/(x-1)# The removal of the factor (x - 2) indicates a hole at x = 2
The graph of
#2/(x-1)# is the same as# (2x-4)/(x^2-3x+2)#
#"but without the hole"# The denominator of f(x) cannot be zero as this would make f(x) undefined. Equating the denominator to zero and solving gives the value that x cannot be and if the numerator is non-zero for this value then it is a vertical asymptote.
#"solve "x-1=0rArrx=1" is the asymptote"# Horizontal asymptotes occur as
#lim_(xto+-oo),f(x)toc" ( a constant)"# divide terms on numerator/denominator by the highest power of x, that is
#x^2#
#f(x)=(2/x^2)/(x^2/x^2-(3x)/x^2+2/x^2)=(2/x^2)/(1-3/x+2/x^2)# as
#xto+-oo,f(x)to0/(1-0+0#
#rArry=0" is the asymptote"#
graph{2/(x-1) [-10, 10, -5, 5]}