I would like help with calculating the volumes of region R in parts (b) and (c), I'm not sure where to start

y = 1 - cos x O 3. Let R be the shaded region in the first quadrant enclosed by the graphs of y = e"*, y = | - cos x, and the y-axis, as shown in the figure above. (a) Find the area of the region R (b) Find the volume of the solid generated when the region R is revolved about the x-axis. (c) The region R is the base of a solid. For this solid, each cross section perpendicular to the x-axis is a square. Find the volume of this solid