这题怎么做？---Let $g : R \to R, g(x) = ax^3 + bx^2 + c$ where $a, b, c \in R$ and $h : R \to R, h(x) = \frac{x^2}{4}$ The graph of $y = g(x)$ passes through the point $(0, 9)$. The graphs of $y = g(x)$ and $y = h(x)$ pass through the point $(6, 9)$ and have the same gradient at this point. The graphs of $y = g(x)$ and $y = h(x)$ are shown below. **Chart/Diagram Description:** * **Type:** Coordinate plane with two functions plotted. * **Coordinate Axes:** * X-axis labeled 'x' points horizontally to the right. The origin O is marked at (0, 0). * Y-axis labeled 'y' points vertically upwards. * **Functions:** * A dashed curve labeled 'y = g(x)' starts on the left, goes through approximately (0, 9), then curves downwards before possibly curving upwards further to the right. It passes through the point (6, 9). * A solid curve labeled 'y = h(x)' starts at the origin (0, 0), curves upwards, representing a parabola opening upwards. It passes through the point (6, 9). * **Points:** * The point (0, 9) is marked on the Y-axis and lies on the dashed curve y = g(x). * The point (6, 9) is marked with a solid circle and lies on both the dashed curve y = g(x) and the solid curve y = h(x). A dashed line segment extends from (6, 9) upwards, tangent to both curves at that point, indicating they have the same gradient. * The origin O is marked at (0, 0), and the solid curve y = h(x) appears to pass through it. Find the values of $a$, $b$ and $c$.