The diagram shows part of the graphs of

\(y=4x^{\frac23} \qquad\text{and}\qquad y=(x-3)^2.\)

The graph of \(y=(x-3)^2\) meets the \(x\)-axis at the point \(A(a,0)\), and the two graphs intersect at the point \(B(b,4)\).

(a) Find the value of \(a\) and of \(b\).

(b) Find the area of the shaded region.