-
samuel minato
- Newbie | Next Rank: 10 Posts
- Posts: 4
- Joined: Wed Nov 30, 2011 8:27 pm
Sn=(2008/2)*(1+2/5)=1004*(7/5)=1405.6
samuel minato wrote:how to solve this?
f(x) = 2/(4^x + 1)
find the value of
f(1/2009) + f(2/2009) +... + f(2008/2009)
maths
This topic has expert replies
Source: Beat The GMAT — Problem Solving |
-
pemdas
- Legendary Member
- Posts: 1084
- Joined: Fri Apr 15, 2011 2:33 pm
- Thanked: 158 times
- Followed by:21 members
ballpark immediately the function part the first term=2/(4^1/2009 +1)=2/(4^0 +1)=1 as 1/2009 is so small close to 0 and the last term 2/(4^2008/2009+1)=2/(4^1+1)=2/5, as 2008/2009 is close to 1, "n"=2008
Sn=(2008/2)*(1+2/5)=1004*(7/5)=1405.6
Sn=(2008/2)*(1+2/5)=1004*(7/5)=1405.6
Success doesn't come overnight!
