no reply??[2]
13 Answers
(3√3 +5)2n+1 =α+β
let (3√3-5)2n+1 =f
now f(α+β)= (3√3-5)2n+1 X (3√3 +5)2n+1 = 22n+1
=> f = [2/ (3√3 +5)]2n+1 <1 [as manish bhaiya told]
now α+β+f = (3√3 +5)2n+1 + (3√3-5)2n+1
=> α+β+f = 2 (2n+1C0 (3√3)2n+1 + .............+ 52n+1) = not an integer
=> but, α+β+f = I (intger) + F(fraction)
this I will obviously be an even integer (2 is there in the front :P)
and I is divisible by 10.
but i dunno how the prev integer is divisible by 3 ....
in fact, it is the next integer that is divisible by 3...
awesome work sky.
@abhirup.. this is a very standard trick question, which i think cannot be solved if you have not seen one of this type earlier...
yeah.... dats true...
but bhaiya :P
ans kuchh aur hai.... ans nahi mila....
ruko fir padhna hoga.. 1 will be back in 10 mins.. then i will post the full answer :)
well... then,
a+b - f = 2m (an even integer)
so b-f = 2m - a = intgr
0<=b<1 , 0<=f<1
so b-f =0 => a = 2m
but then again it is an even integer...
and the last term, will not have any 3 in it... so how can it be a multiple of 3 //
help :'(
sorry din see
I think wrong options...
I think the answer is incorrect