某数的绝对值的算术平方根等于它本身,这个数必为( ) A.1或-1 B.1或0 C.-1或0 D.1,-1或0
问题描述:
某数的绝对值的算术平方根等于它本身,这个数必为( )
A. 1或-1
B. 1或0
C. -1或0
D. 1,-1或0
答
设该数是a,则根据题意,得
=a(a≥0),
|a|
∴|a|=a2
a只能是:1,0.
故选B.