341Direct AM-GM will give you option (a)
if a1,a2,a3,....,an are +ve real nos whose product is a fixed real no. 'c',
then the minimum value of a1+a2+a3+......+2an-1 + 2an is --
a) n(4c)1/n
b) (n+1) c 1/n
c) 2nc1/n
d) (n+1)(2c)1/n
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7 Answers
1no it is not a typo bhaiya..
dat is only my doubt!!
where from those came suddenly...
341Ok, instead of 2an-1 and 2an write a'n-1 and a'n
Then the problem is:
Given +ve real nos. a1 a2a3....a'n-1a'n = 4c,
find the maximum of
a1 + a2+ a3+...+a'n-1+ a'n
This you know how to solve
62yeah that is ok prophet.. but how can we be sure how only the last 2 terms are 2.an not the other terms in between! :O
341I didnt have reason to suspect, because the answer tallied with option (a) :D
Otherwise skygirl would have had a lot to answer for :D :D