C

D

X

O

P

A

Y

23.( 1 1) As shown in the figure, in the plane rectangular coordinate system, a straight line intersects a parabola at two points, point A is on the axis, and the ordinate of point B is 3. Point P is a moving point on the parabola below straight line AB (which does not coincide with A and B), and the intersection of the vertical line with point P and point C is PD ⊥.

(1).

(2) The abscissa of point P is

① The length of line segment PD is expressed by algebraic expression,

And find out the maximum length of the line segment PD;

② Connect PB and divide the line segment PC into two parts.

Whether the two triangles have proper values,

Make the area ratio of these two triangles 9: 10?

If it exists, write the value directly; If it does not exist, explain why.

23, (1) times to get ⅷ.

Get ⅷ from

After two points,

∴

Let a straight line intersect the axis at a point, and then

∑ axis, ∴

∴

(2) According to (1), the analytical formula of parabola is

∴

Yes,

At the right time, there is a maximum.

(2) there are values that meet the conditions,

point out

The ones passing through point D and point B respectively are DF⊥PC, and the vertical feet are F and G respectively.

Yes,

and

∴

When? solve

When will it be solved?