the limiting sum of a geometric series is 5 and the 2nd term is 6/5. find the first term and the common ratio.
sorry bt can u say again wht's the role of 5
its the limiting sum
|dw:1371289824437:dw| so its that
thats the limiting sum formula
i'm doing geometric series bt haven't yet came across limiting sum!
you should come across it soon
ahan
Now if you're given the second term,which is 6/5, hw would you use this to find the first term in the sequence? :)
not sure
what the name of this formula ?
geometric series.
like first term is \(a_1\), 2nd term, you just multiply by r, 2nd term = \(a_1r\), 3rd term, you again multiply by r, 3rd term = \(a_1r^2\) terms ----> \(a_1,a_1r,a_1r^2,a_1r^3....\) so, general term = \(a_n=a_1r^{n-1}\) here you have ar = 6/5 and a/(1-r) =5 solv simultaneously...
hmm...
a= 6/(5r)
ar = 6/5 therefore a = 6/5r lol..... -_- \[\huge \frac{\frac{6}{5r}}{1-r}=5\]
yes^
@yasmin95 could u solve now ?
yes thanks :)
welcome ^_^
\[\large \frac{6}{5r}= 5-5r\]\[\large 5r + \frac{6}{5r}=5\] Im too l azy.
quadratic equation...i guess yasmin already solved it :)
I don't even know.....how to.... :| havent bothered, lol.
@yasmin95, how did you solve thiss
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