matlab用三种方法求解二阶微分方程x''+0.2x'=0.4x=0.2u(t),u(t)是单位阶跃函数,初始状态为0

x''+0.2x'-0.4x=0.2u(t), x(0)=x'(0)=0.1.你用Laplace Transform 做吧.L(x'')+0.2L(x')-0.4L(x)=0.2L(u(t))(p^2)*X(p)-p*x(0)-x'(0)+0.2(p*X(p)-x(0))-0.4*X(p)=0.2/p,(p^2+0.2*p-0.4)*X(p)=0.2/p,X(p)=0.2/(p^3+0.2...