Ut Au 2 Vu, for x E Br(0) CR3 O for x e Br(0) u If u is a smooth solution, prove that the energy E(t) = 1 BA 1 u? (t)e-171/28 BR(0) decreases with time. You may assume that E(t) is finite and that y Ut Au 2 Vu, for x E Br(0) CR3 O for x e Br(0) u If u is a smooth solution, prove that the energy E(t) = 1 BA 1 u? (t)e-171/28 BR(0) decreases with time. You may assume that E(t) is finite and that y