Estimating Sums of Alternating Series help

[Slimsta]

Homework Statement

[PLAIN]http://img696.imageshack.us/img696/3438/46981606.jpg

Homework Equations

The Attempt at a Solution

in those squars, I am sure about everything that i did and i get it wrong..
the only thing i don't know is b_n+1 how would i know if its =, < or > than 0.008 ?

once i know that, everything else just follow it..

 

[Slimsta]

someone please?

 

[lanedance]

i haven't checked your working, but doesn't it ask for n as "an integer"?

 

[rs1n]

The Attempt at a Solution

in those squars, I am sure about everything that i did and i get it wrong..
the only thing i don't know is b_n+1 how would i know if its =, < or > than 0.008 ?

once i know that, everything else just follow it..

First, note that n is supposed to be NATURAL NUMBER. So can n have trailing digits after the decimal place? As for whether you should have =, <, or >... reread both the problem statement (the error should be less than .008) as well as the Alternating Series Estimation Theorem (consider the relationship between $b_{n+1}$ and the error).