Question

√1+3+5+...+2013 apartineQ

Answer 1

1 + 3 + 5 +...+ x = [(x+1)/2]^2. (formula mai rapida)

1 + 3 + 5 +...+ 2013 = [(2013+1)/2]^2 =
= (2014/2)^ 2 = 1007^2

=> √1007^2 = 1007 apartine lui Q