Aspecial liquid is held in a tank described as (x 2 + y 2 ) ≤ z ≤ 1 in a cartesian coordinate system. assume that the density of the liquid at point (x, y, z) is rho(x, y, z) = (2 − z 2 ), provided that the point is actually in the tank. find the total weight of the liquid by integrating rho dx dy dz.