Mathematics
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OpenStudy (anonymous):
@satellite73
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OpenStudy (anonymous):
yes?
OpenStudy (anonymous):
\[\large \bf \frac{x+1}{(x-1)^2}\]
Find the value of x
OpenStudy (anonymous):
?
OpenStudy (anonymous):
sorry.....
OpenStudy (anonymous):
is there an equation?
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OpenStudy (anonymous):
\[\large \bf \frac{x+1}{(x-1)^2}<1\]
Find the value of x
OpenStudy (anonymous):
use this formula ( a+ b +^2 = a^2 +b^2 +2ab
OpenStudy (anonymous):
oh crap
OpenStudy (anonymous):
\[\large \bf \frac{x+1}{(x-1)^2}<1\\
\large \bf \frac{x+1}{(x-1)^2}-1<0\] of course
then subtract
OpenStudy (anonymous):
ooh no hold the phone
easier than that!
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OpenStudy (anonymous):
\[\frac{x+1}{(x-1)^2}<1\] since \((x-1)^2>0\) then you can multiply both sides by \((x-1)^2\)
OpenStudy (anonymous):
then
OpenStudy (anonymous):
giving
\[x+1<(x-1)^2\]
OpenStudy (anonymous):
multiply out on the right
OpenStudy (anonymous):
\[x+1<x^2-2x+1\]
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OpenStudy (anonymous):
\[\large \bf x+1<x^2+1-2x\]
\[\large \bf -x^2+3x<0\]
OpenStudy (anonymous):
make your life simpler and ue
\[x^2-3x>0\]
OpenStudy (anonymous):
then,
\[\large \bf x^2-3x>0\]
OpenStudy (anonymous):
right
OpenStudy (anonymous):
\[\large \bf x(x-3)>0\]
\[\large \bf x>0,3\]
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OpenStudy (anonymous):
right?
OpenStudy (anonymous):
hmm no
OpenStudy (anonymous):
why?
OpenStudy (anonymous):
well for one thing \(x>0,3\) makes no sense
OpenStudy (anonymous):
so what is the correct way of writing?
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OpenStudy (anonymous):
your answer is two intervals, so you need either interval notation or inequality notation
OpenStudy (anonymous):
oh!! k
OpenStudy (anonymous):
like i said before, we are not done
we only know where it changes sign
you have to find where it is positive
i.e. where \(x(x-3)>0\)
OpenStudy (anonymous):
so intervals are :-
|dw:1398229869152:dw|
\[\large \bf (-\infty,0)U(3,\infty)\]