Is n an integer?
1) n2 is an integer
2) sqrt n is an integer
is someone can show me an example of n2 not beeing an integer will be very much appreciated.
1) if n^2 is an integer: for example n^2 = 3 -> n = sqrt(3) - not an integer; n^2 = 4 -> n = 2 - integer -> insufficient
2) sqrt(n) is an integer -> n = sqrt(n)*sqrt(n) = integer -> sufficient -> B