Mathematics
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OpenStudy (lisa123):
f(x)= x^3-1/ x^2+x+1. Find the domain, zeros, holes, and asymptotes
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OpenStudy (anonymous):
do you know how to factor the difference of two cubes?
OpenStudy (lisa123):
(x-1)(x^2+x+1)
OpenStudy (anonymous):
yes
OpenStudy (anonymous):
now cancel and you are done
OpenStudy (lisa123):
I don't know how to factor the denominator
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OpenStudy (anonymous):
take a look at your numerator in factored form
OpenStudy (lisa123):
ohhhhh wowww
OpenStudy (anonymous):
\[\frac{(x-1)(x^2+x+1)}{x^2+x+1}\] no need to factor
in fact you cannot factor further, \(x^2+x+1\) has no zeros
OpenStudy (lisa123):
so what is the domain?
OpenStudy (anonymous):
since the denominator has no zeros, the domain is all real numbers
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OpenStudy (anonymous):
normally you would say "all real numbers except for the zeros in the denominator" but this denominator doesn't have any
is it clear why?
OpenStudy (lisa123):
yeah b/c it can only be factored with imaginary numbers
OpenStudy (anonymous):
right
OpenStudy (lisa123):
what are the asymptotes....I know its oblique
OpenStudy (anonymous):
hold the phone
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OpenStudy (anonymous):
the whole thing is just the line \(f(x)=x-1\)
OpenStudy (anonymous):
it is a line
it does not have asymptotes
OpenStudy (lisa123):
I thought you looked for the horizontal asymptote based on the exponents
OpenStudy (anonymous):
normally you would
OpenStudy (anonymous):
but in this case the entire denominator cancels
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OpenStudy (anonymous):
\[\frac{(x-1)(x^2+x+1)}{x^2+x+1}=x-1\]
OpenStudy (lisa123):
oh alright thank you!