2 Answers
Anirudh Kumar
·2009-12-17 02:01:49
Let (8+3√7)20 = I+f where I =[(8+3√7)20 ] and 0<f<1
now (8-3√7)20 =d
we find that 0,<8-3√7<1
=> 0<d<1
now
I+f+d= (8+3√7)20+(8-3√7)20
=> I+f+d= 2K (where k=integer)
=> f+d= integer
also 0<f+d<2
=>f+d=1
=>I=2k-1
thus I is odd.
[(8+3√7)20] is odd