Mathematics
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OpenStudy (anonymous):
compute the sum
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OpenStudy (anonymous):
\[\sum_{i=0}^{101}\frac{ x _{i}^3 }{ 1-3x _{i} +3x _{i}^2}\]
\[x _{i}=1/101\]
OpenStudy (anonymous):
\[x _{1}=1/101\]
OpenStudy (anonymous):
I think you're missing some rule for xi in terms of i
OpenStudy (anonymous):
imeant x1 not xi
OpenStudy (anonymous):
x1=1/101
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OpenStudy (anonymous):
the solution is quite easy
OpenStudy (anonymous):
is your answer supposed to be in terms of xi?
because you haven't included a rule for x in terms of i
OpenStudy (anonymous):
oh i see its\[x _{i}=\frac{ i }{ 101 }\]
OpenStudy (anonymous):
does that help
OpenStudy (anonymous):
\[\frac{ -x^3 }{ (x-1)^3-x^3 }\]
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OpenStudy (anonymous):
yeah
OpenStudy (anonymous):
from here i thinthe denominator is easy to work with cos two consecutiver cubes cancel
OpenStudy (anonymous):
or we can work out
\[\frac{ 1 }{ 1-(\frac{ x-1 }{ x })^3 }\]
OpenStudy (anonymous):
\[\frac{ 1 }{ 1-(1-\frac{ 1 }{ x })^3 }\]
OpenStudy (anonymous):
\[\sum_{i=0}^{101}=(1-1/x _{i})=?\]
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OpenStudy (anonymous):
error
OpenStudy (anonymous):
\[\sum_{i=0}^{101}x _{i}^{3}=\frac{ 1 }{ 101^3 }(0+1^3+2^3+3^3+4^3+5^3+...+102^3)\]
\[\sum_{i=0}^{101}(x_{i}-1)^3= \frac{ 1 }{ 101^3 }((-1)^3+0+1^3+2^2+... +101^3)\]
difference
OpenStudy (anonymous):
\[=\frac{ 1 }{ 101^3 }(1+102^3)\]
OpenStudy (anonymous):
\[\frac{ (0+1^3+2^3+3^3+4^3+...+102^3) }{ 1+102^3 }\]
OpenStudy (anonymous):
wolfram=51
i have no idea
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OpenStudy (anonymous):
@hartnn can you pls help
OpenStudy (anonymous):
i made mistake with \[(x-1)^3\]
sum
OpenStudy (anonymous):
\[\sum_{i=0}^{101}(x_i-1)^3=\frac{ -1 }{ 101^3 }(101^3+100^3+99^3+...0^3+1^3)\]
OpenStudy (anonymous):
sum\[(\frac{ 2 }{ 101^3})(0+1+3^3+...+101^3)+\frac{ 102^3 }{ 101^3 }=\frac{ 2(0+1+3^3+...+101^3)+102^3 }{ 101^3 }\]
OpenStudy (anonymous):
total
\[\frac{ 0+1+3^3+...+102^3 }{2(0+1+1+3^3+... 101^3 )+102^3}\]
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OpenStudy (anonymous):
unsloved
OpenStudy (anonymous):
solved