1, among the following trigonometric function values, the negative value is ();
a . sin(-6600)b . tan(- 1600)c . cos(-7400)d . sin(-4200)cos 570
2. The angle α is the angle of the second quadrant. If │ │ =, the angle belongs to: ()
A. the first quadrant; B. the second quadrant; C. the third quadrant; D. the fourth quadrant
3, known, is the angle of the second quadrant, and then ()
A.; b; c; D. none of the above is correct.
4. The increasing interval of function y= sin(2x+) is ().
A.[- ] B. [- ] C. [- ] D. [- ]
5. known -x