(1) Let , x> 0. Find the minimum value of a for which f(x) is strictly decreasing on [a, ∞).

5. The tangent line to the curve y = x3 at the point A(1,1) intersects the curve at another point B. Let R be the area of the region bounded by the curve and the tangent line. The tangent line at B intersects the curve at another point C. Let S be the area of the region bounded by the curve and the second tangent line. Find the values of R and S.