Q5. Diagram NOT accurately drawn R The region R, shown shaded in Figure, is bounded by the curve with equation ! y = ex, the curve with equation y = 4e , the straight line with equation ! x = a, the x-axis and the y-axis. When the region R is rotated through 360" about the x-axis, the volume of the solid generated is k- Bre- where k is a constant. Using algebraic integration, find a possible value of a and the exact corresponding value of k. (8)