Let u(x,t) be the solution of the initial-boundary value problem utt−uxx+ut=0,0<x<π,t>0,u(0,t)=0,u(π,t)=0,t>0,u(x,0)=sinx,ut(x,0)=0,0<x<π. For t≥0, define E(t)=∫0π(ut2+ux2) dx. Then which of the following statements are true?
Multi-select · full marks only for the exact set · Partial Differential Equations