问题
选择题
函数y=
|
答案
∵x＞1，
∴y=
=x2+8 x-1
+x2-1 x-1 9 x-1
=（x+1）+9 x-1
=（x-1）+
+29 x-1
≥2
+2=8；(x-1)× 9 x-1
故选C．
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函数y=
|
∵x＞1，
∴y=
=x2+8 x-1
+x2-1 x-1 9 x-1
=（x+1）+9 x-1
=（x-1）+
+29 x-1
≥2
+2=8；(x-1)× 9 x-1
故选C．