Consider the wave equation problem U - 1.21 = 0,0 0 with initial conditions u(x,0) = sin (nr -0.25x), 0x1 u(,0)=0, 0x1 and boundary conditions u (0,t)=0, t>0 u(1,1)=0 t > 0 1.1) If Ar= 0.2 what are the possible values of At to ensure stability? EE 1.2) Approximate the solution to the above problem at t = 0.3 using finite differences with Ar= 0.25 and At = 0.1 I