# Math Help - sequence question

1. ## sequence question

The general term of a series is tn= pie(3/11)^n+1, how many terms must be added to reach a sum that is greater than 0.32

the only problem is,when I substitue 1 in for n...I already get a sum bigger than 0.32,the question is out of 4 marks,so I know thats not the answer....I'm stumped

2. Originally Posted by dan123
The general term of a series is tn= pie(3/11)^n+1, how many terms must be added to reach a sum that is greater than 0.32

the only problem is,when I substitue 1 in for n...I already get a sum bigger than 0.32,the question is out of 4 marks,so I know thats not the answer....I'm stumped
You need the sum of the series rather than the general term of a series:

Did you mean $t_n = (\frac{3\pi}{11})^{n+1}$ or

$t_n = (\frac{3\pi}{11})^n +1$

3. the pie is outside of the bracket,with the (3/11) inside the bracket so pie(3/11) then yeah the n+1 is an exponent

4. I read the question as $S_n = \sum\limits_{k = 1}^n {\pi \left( {\frac{3}
{{11}}} \right)^{k + 1} }$
and $S_n>0.32$ if $n\ge 5$.