Pls help me to solve this question

ai A cuboid has a square base with sides of xcm. The height at the cuboid ls twice the length of the side of its base. Given that 1: increases at the rate of 0.020113". find the rate at change at the volume when the total surface area Is 160cm. [7 Marks] bi Given 1! I- x3 + 8x - 7. Find the coordinates of the stationary points and determine the nature of the cum and sketch the graph. [a Marks]