22.(9 o'clock) As shown in the figure, in the rectangular coordinate system, the coordinate of point A is (-2,0), connect OA, and rotate the line segment OA clockwise around the origin o 120 to get the line segment OB.

(1) Find the coordinates of point B;

(2) Find the analytical formula of parabola passing through points A, O and B;

(3) Is there a point C on the axis of symmetry of the parabola in (2) that minimizes the circumference of △BOC? If it exists, find the coordinates of point C; If it does not exist, please explain why.

(4) If point P is the moving point on the parabola in (2) and below the X axis, is the area of △PAB the largest? If yes, calculate the coordinates of point P and the maximum area of delta delta △PAB at this time; If not, please explain why.

23. As shown in the figure, in the plane rectangular coordinate system, the straight line L: Y =-2x-8 intersects the X axis and the Y axis at two points A and B respectively, and the point P(0, k) is a moving point on the negative semi-axis of the Y axis, with P as the center and 3 as the radius.

(1) Connect PA, if PA=PB, try to judge the position relationship between ⊙P and X axis, and explain the reasons;

(2) When k is what value, is the triangle whose vertex is ⊙P and the intersection of straight line L and center p a regular triangle? ?

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