1. In the rectangular coordinate system, point A (3 3,0) is on the Y axis.
2. In the rectangular coordinate system, the abscissa of any point on the X axis is 0.
3. In rectangular coordinate system, point A (1, 1) is in the first quadrant.
4. In rectangular coordinate system, point A (-1, 1) is in the second quadrant.
5. In rectangular coordinate system, point A (-1,-1) is in the third quadrant.
6. In rectangular coordinate system, point A (1,-1) is in the fourth quadrant.
Basic knowledge of junior high school mathematics: special trigonometric function value
1.cos30 =√3/2
2.sin2 60 + cos2 60 = 1
3.2 indium 30+tantalum 45 = 2
4.tan45 = 1
5.cos60 + sin30 = 1
Basic knowledge of junior high school mathematics: the basic nature of circle
1. The circumferential angle of a semicircle or diameter is a right angle.
2. Any triangle must have a circumscribed circle.
3. In the same plane, the distance to a fixed point is equal to the trajectory of a fixed-length point, which is a circle with the fixed point as the center and the fixed length as the radius.
4. In the same circle or equal circle, the circular arcs with equal central angles are equal.
5. The angle of the circle opposite to the same arc is equal to half the central angle of the circle.
6. The same circle or the same circle has the same radius.
7. You can make a circle after three o'clock.
8. Two equal-length arcs are equal-length arcs.
9. In the same circle or equal circle, the circular arcs with equal central angles are equal.
10. The diameter of the chord bisected by the center of the circle is perpendicular to the chord.