Find the sum of the geometric sequence.
1/4, 1/16, 1/64, 1/256
I don't know where to start
it's geometric sequence firs step to find ratio you can find ratio \[\huge\rm r = \frac{ a_2 }{ a_1} , \frac{ a_4 }{ a_3 }\] divide next term by one previous one to get ratio
there are two formulas to find sum of geometric sequence one is infinite geometric sequence and 2nd one is finite geometric sereies use this formula for infinite geometric when \[\left| r \right| <1\]\[\huge\rm s_n = \frac{ a_1 }{ 1-r }\] and if ratio is greater than then apply this formula finite geometric series \[\huge\rm s_n = a_1 (\frac{ 1 - r^n }{ 1-r })\]
ok so r= 1/4
yes that's right which is less than one so you suppose to find finite or infinite geometric sum ??
infinite geometric sum
yep right a_1 first term r= ratio :-) solve that
ok so 1/1-(1/4) = 4/3? the first term is 1, I accidently started in 1/4
first term is 1 ???
yes
1/4, 1/16, 1/64, 1/256 first term is what ??
it goes 1, 1/4, 1/16...
I typed it in wrong at the beginning. I forgot to put one first
ohh okay
so what do I do with 4/3 next
\[\huge\rm \frac{ 1 }{ 1 - \frac{ 1 }{ 4 } }\] = 4/3 yes done
one of the options is 341/256. That's the same thing right?
hmmm not sure what are other options ?
341 1/192 1/768
yep that's the only one make sense to me
Yeah it makes sense to me too. Thank you @Nnesha
np :-)
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