Consider the conduction of heat in a rod 40 cm in length whose ends are maintained at 0°C for all >0. In each of Problems 9 through 12, find an expression for the temperature u(x,t) if the initial temperature distribution in the rod is the given function. Suppose that a² = 1. 0, (11.) u(x, 0) = | 50, 0≤x≤10, 10 ≤ x ≤ 30, 0, 30 < x < 40