For the following exercises, draw the region bounded by the curves. Then, find the volume when the region is rotated around the y-axis. 82. y = 4 - 2x, x = 0, and y = 0 83. y = 2x', x = 0, x = 1, and y = 0 84. y = 3x2, x =0, and y = 3 85. y = V4 - x2, y = 0, and x = 0