1. (10 points) Solve the heat ow problem Bu 621; E=4632' t>0,0 , 3a ,t =0, t>0, 6x\" ) u(a:,0)=2c052:+50053$, US$311". [In this problem and the following ones, it is not necessary to repeat the separation of variables: you may use the appmpriate formal solution of the PDE and boundary conditions found in notes and lectures] 2. (10 points) Solve the heat ow problem 2:=3%, t>0, 0 0, u(1,t) =1, t>0, u(a:,0)=:c2, Ong 1. Then nd \"mg'00 u(m, t)