3. Let R be the region enclosed by the graphs of y=e", y=x', and the y-axis. a) Find the area of R. b) Find the volume of the solid with base on region R and cross sections perpendicular to the x- axis. The cross sections are triangles with height equal to three times the length of their base. c) Find the volume of the solid with base on region R and cross sections perpendicular to the y- axis. The cross sections are rectangles with height equal to six times the length of their base.