Mathematics
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OpenStudy (anonymous):
Please Help me out...
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OpenStudy (anonymous):
\[\large \bf 2x^2+\frac{1}{x}>0\]
Find the intervals of x
OpenStudy (anonymous):
add
OpenStudy (anonymous):
oh wow this is going to suck
OpenStudy (anonymous):
\[\large \bf \frac{2x^3+1}{x}>0\]
OpenStudy (anonymous):
\[\frac{2x^3+1}{x}>0\] is a start
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OpenStudy (anonymous):
then,
OpenStudy (anonymous):
then we know the sign changes at \(x=0\) for the denominator
OpenStudy (anonymous):
for the numerator it changes at \(-\frac{1}{\sqrt[3]{2}}\)
OpenStudy (anonymous):
how?
OpenStudy (anonymous):
please show your work
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OpenStudy (anonymous):
so the answer is nice and ugly
but no matter
OpenStudy (anonymous):
\[2x^3+1=0\\
2x^3=-1\\
x^3=-\frac{1}{2}\\
...\]
OpenStudy (anonymous):
then,here i stuck
OpenStudy (anonymous):
take the cube root and get \(x=-\frac{1}{\sqrt[3]{2}}\)
OpenStudy (anonymous):
yeah!!! thank you
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OpenStudy (anonymous):
oh, you mean stuck as to finding the answer to the original question? we are not done
OpenStudy (anonymous):
what we are not done mean?
OpenStudy (anonymous):
you still have to solve where it is positive, your answer should be intervals (2 intervals)
OpenStudy (anonymous):
yeah... i can do that...
OpenStudy (anonymous):
thanks..
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OpenStudy (anonymous):
k you want me to check, or is it obvious?
OpenStudy (anonymous):
am i right or not?
answer=\[\large \bf (-\infty,\frac{-1}{\sqrt[3]{2}})U(0,\infty)\]