A.M≥0                                B.M＞0

C.M＜0                                D.M时正时负

A.10              B.               C.-10              D.-

A.第一、二象限                      B.第一、三象限

C.第一、四象限                      D.第二、四象限

①y=  ②y=secα  ③y=cscα  ④y=

A.1               B.2               C.3                D.4

(1)求α的集合；

（2）判断sin,cos,tan的符号.

(1)sin105°·cos230°;

(2)sin·tan;

(3)cos6·tan6;

(4)sin4·tan().

(1)tan125°·sin273°;

(2);

(3)sin·cos·tan;

(4);

(5)tan191°-cos191°;

(6)sin3·cos4·tan5·cot6.

(1)y=sinx+cosx;

(2)y=+tanx.