先化简，再求值：（ 1x−1 ﹣ 1x+1 ）÷ x+2x2−1 ，其中x=2sin30°+2 2 cos45°．_刷题宝

题干

先化简，再求值：（ −

1

x

1

﹣

1

x

+

1

）÷ −

x

+

2

x

2

1

，其中x=2sin30°+2 2 cos45°．

上一题下一题 0.0难度选择题更新时间:2019-03-27 04:01:02

答案(点此获取答案解析）

解：原式=

\frac{(x + 1) - (x - 1)}{}

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