请教一道DS题

Economics

Is n an integer?
(1) n^2 is an integer
(2) (sqr)n is an integer
注：(sqr)是开根号

答案是B，为什么单独条件一不充分？

tangjinxiong

if n is (sqr)2, n^2=2 is an interger, but n is not an interger

Economics

Thanks a lot.

ps: your spelling of integer is wrong