计算：（1）sin25π6+cos26π3+tan(-25π4)（2）已知x+1x=3，求3x-xx2+x-2-2的值．

题干

计算：

（1）sin25π

6

+cos26π

3

+tan(-25π

4

)

（2）已知x+

1

x

=3，求

的值．

上一题下一题 0.0难度选择题更新时间:2016-02-17 06:05:46

解：（1）sin25π

6

+

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