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任意角三角函数的概念

> ①存在 α∈(0， π 2 )使 sina+cosa= 1 3 ； ②存在区间（a，b）使y=cosx为减函数而sinx＜0； ③y=tanx在其定义域内为增函数； ④ y=cos2x+sin( π 2 -x)既有最大、最小值，又是偶函数； ⑤ y=sin|2x+ π 6 |最小正周期为π．以上命题正确的为______．

问题：

发布时间：2024-09-08

①存在 α∈(0，

π

2

)使 sina+cosa=

1

3

；
②存在区间（a，b）使y=cosx为减函数而sinx＜0；
③y=tanx在其定义域内为增函数；
④ y=cos2x+sin(

π

2

-x)既有最大、最小值，又是偶函数；
⑤ y=sin|2x+

π

6

|最小正周期为π．
以上命题正确的为______．

参考答案：

提问用户：Co***xw4

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