What are the asymptotes and removable discontinuities, if any, of #f(x)=(x-3)/(2x+5)#?

1 Answer
Mar 31, 2018

#"vertical asymptote at "x=-5/2#
#"horizontal asymptote at "y=1/2#

Explanation:

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 "2x+5=0rArrx=-5/2" is the asymptote"#

#"Horizontal asymptotes occur as"#

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

#"divide terms on numerator/denominator by x"#

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

#"as "xto+-oo,f(x)to(1-0)/(2+0)#

#rArry=1/2" is the asymptote"#

#"Removable discontinuities occur when common"#
#"factors are cancelled from the numerator/denominator."#
#"this is not the case here hence there are no removable"#
#"discontinuities"#
graph{(x-3)/(2x+5) [-10, 10, -5, 5]}