Problem 12. (1 point) A one-meter long bar is heated unevenly, with temperature in CC at a distance x meters from one end at time t given by H(x,t) = 120e_0'15t sin(7tx) 0 S x g 1. On a sheet of paper, sketch a graph of H against x for t = 0 and t = 1. Think about why your graphs make sense. (a) Calculate each of: Hx(0.2,t) = Hx(0.8,t) = (Be sure that you can say in words what the practical interpreta- tion ( in terms of temperature) of these two partial derivatives is, and why each has the sign that it does.) (b) Calculate: Hit/31\") = . (Again, he sure that you understand why it has the sign that it does, and what its interpretation in terms of temperature is.) Answer(s) submitted: (incorrect)