B

Part of the graph of the function \(f(x) = \frac{1} {x}\) is shown in the picture. Consider the region bounded by \(x\)-axis, graph of \(f\) and lines \(x = 1\) and \(x = 4\). Find the volume of the solid of revolution obtained by revolving this region about \(x\)-axis.

Consider the parabola \((x - 4)^{2} = 8(y + 1)\). Find the vertex of this parabola.

Consider the parabola \((y - 1)^{2} = 12(x - 1)\). Find the focus of this parabola.

Parabola is a set of the points that are equidistant from the point (focus) and the line (directrix). Find the directrix of the parabola \((x - 3)^{2} = 8y\).