问题
解答题
已知a+
|
答案
∵(a+
) 2=a2+2a•1 a
+1 a
=a2+2+1 a2 1 a2
∴a2+
=(a+ 1 a2
)2-21 a
=(-1+
)2-210
=1-2
+10-210
=9-2
．10
搜题请搜索小程序“爱下问搜题”
已知a+
|
∵(a+
) 2=a2+2a•1 a
+1 a
=a2+2+1 a2 1 a2
∴a2+
=(a+ 1 a2
)2-21 a
=(-1+
)2-210
=1-2
+10-210
=9-2
．10