How do you identify all asymptotes or holes and intercepts for f(x)=(x^3-4x)/(x^2-x)?

1 Answer
Nov 27, 2017

V.A. x=0,x=1
H.A. non
S.A. x+1
HOLE. (0,4)

Explanation:

. For a function to have V.A. the function needs to have undefined points (zeros of denominator)
In this function, the zeros of the denominator are 0 and 1 therefore the vertical asymptotes are x=0 and x=1

. A graph will have a horizontal asymptote if the degree of the denominator is greater than the degree of the numerator
In this function, the degree of nominator is 3 and the degree of numerator is 2
3>2 so there is no Horizontal asymptote

. Since the degree is one greater in the numerator, I know that I will have a slant asymptote.
Use polynomial long division to get the Slant/Oblique asymptote
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S.A. : x+1

.There is a hole at (0,4)

(x^3-4x)/(x^2-x)

factor x from numerator and denominator
rewrite 4 as 2^2

(x(x^2-2^2))/(x(x-1)

factor

(x(x+2)(x-2))/(x(x-1))
the common factor is x