Problem 1 : Find the steady state temperature of a laterally insulated rod subject to the following conditions. Length of the rod 20, left end insulated and right end held at 100 I am not sure if i fully understand this problem, is this asking me to list the Boundary value conditions ? like , u(x,0) = 10 , u(x,20) = 100, u_x (0) = 0 ? or a function ? Problem 2 : The vertical displacements of a membrane were found to be given by the function u(x,y,t) = cos(15t) sin(3x) cos(4y) , What is the corresponding wave's speed c ? for this problem first i need to take the derivative u'(x,y,t) but with respect to what?