题目内容
若a=
,则(a+1)(a-1)=______.
| 3 | a |
∵a=
,
∴a3=a,
即a(a 2-1)=0,
解得:a=0或a 2-1=0,
当a=0,则(a+1)(a-1)=-1,
当a 2-1=0,则(a+1)(a-1)=a 2-1=0.
故答案为:-1或0.
| 3 | a |
∴a3=a,
即a(a 2-1)=0,
解得:a=0或a 2-1=0,
当a=0,则(a+1)(a-1)=-1,
当a 2-1=0,则(a+1)(a-1)=a 2-1=0.
故答案为:-1或0.
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