点的坐标与函数解析式的关系？---**Question Stem:** As shown in the figure, in a Cartesian coordinate system, A and B are two points on the positive x-axis, and OA = AB. Perpendicular lines are drawn from points A and B to the x-axis, intersecting the parabola y = x^2 at points C and D respectively. Line OC intersects BD at point M, and line CD intersects the y-axis at point H. **Sub-questions:** (1) Find the ratio of the area of triangle CMD to the area of quadrilateral ABMC. (2) Prove: x_C * x_D = -y_H. **Chart/Diagram Description:** * **Type:** A geometric figure displayed in a 2D Cartesian coordinate system. * **Coordinate Axes:** An x-axis (horizontal) and a y-axis (vertical) intersect at the origin O. Arrows indicate the positive directions of both axes. * **Graph:** A parabola represented by the equation y = x^2, which opens upwards and is symmetric about the y-axis, passing through the origin O. * **Points:** * **O:** The origin (0,0). * **A:** A point on the positive x-axis, to the right of O. * **B:** A point on the positive x-axis, to the right of A. The segment OA has the same length as the segment AB (OA = AB). * **C:** A point on the parabola y = x^2. It lies vertically above point A, meaning the line segment AC is perpendicular to the x-axis. * **D:** A point on the parabola y = x^2. It lies vertically above point B, meaning the line segment BD is perpendicular to the x-axis. * **M:** The intersection point of the line segment OC and the line segment BD. M is located between C and D, and between O and D. * **H:** The intersection point of the line segment CD and the y-axis. H is located on the negative part of the y-axis, below O. * **Lines/Segments:** * **AC:** A vertical line segment from A to C. * **BD:** A vertical line segment from B to D. * **OC:** A straight line segment connecting the origin O to point C. * **CD:** A straight line segment connecting point C to point D. * **OM:** The part of line OC from O to M. * **BM:** The part of line BD from B to M. * **MH:** The part of line CD from M to H. (Note: The diagram shows M and H on the line CD, but M is between C and D, and H is on the y-axis, collinear with C and D).