How do you find the vertical, horizontal and slant asymptotes of: # f(x)= (3x + 5) /( x - 2)#?

1 Answer
Jul 30, 2016

vertical asymptote x = 2
horizontal asymptote y = 3

Explanation:

The denominator of f(x) cannot be zero as this would be 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 of x then it is a vertical asymptote.

solve : x - 2 = 0 → x = 2 is the asymptote

Horizontal asymptotes occur as

#lim_(xto+-oo),f(x)toc" (a constant)"#

divide terms on numerator/denominator by x

#((3x)/x+5/x)/(x/x-2/x)=(3+5/x)/(1-2/x)#

as #xto+-oo,f(x)to(3+0)/(1-0)#

#rArry=3" is the asymptote"#

Slant asymptotes occur when the degree of the numerator > degree of the denominator. This is not the case here (both of degree 1 ) Hence there are no slant asymptotes.
graph{(3x+5)/(x-2) [-20, 20, -10, 10]}