Solve partial differential equation 1. k∙((∂ )/∂x) (∂u/∂x)=(∂u/∂t) , 0<x<L , k>0 , t>0 condition u(0,t)=0 , u(L,t)=0 , t>0 u(x,0)=f(x) , 0<x<L 2. (∂r/∂t)=−α∇^2 r condition r(t,0)=h(t) , 0≤t≤L r(0,t)=r(L,t)=0 , t>0