The diagram below shows a sketch of the curve \(y = f(x)\), where \(f(x) = 10x + 3x^2 - x^3\). The curve intersects the \(x\)-axis at the origin \(O\) and at the points \(A(-2, 0)\), \(B(5, 0)\). The tangent to the curve at the point \(C(2, 24)\) intersects the \(y\)-axis at the point \(D\).
\includegraphics{figure_11}
- Find the coordinates of \(D\). [5]
- Find the area of the shaded region. [6]
- Determine the range of values of \(x\) for which \(f(x)\) is an increasing function. [4]