用dsolve()函数,就可以解决。dsolve('3*D2x+500*Dx+2000*x','Dx(0)=2.5','x(0)=0.1')ans =(565^(1/2)*exp(t*((10*565^(1/2))/3 - 250/3))*(2*565^(1/2) + 65))/22600 + (565^(1/2)*(2*565^(1/2) - 65))/(22600*exp(t*((10*565^(1/2))/3 + 250/3))) %x(t)
ode45可以试验下