syms I(t) S(t) R(t) eq = [diff(I) == 0.003*S*I-0.9857*I; diff(S)==0.9857*S*I; diff(R)==0.9857*I]; conds=[I(0)==5.1325e+06; S(0)==3.2163e+08]; [I,S,R]=dsolve(eq, conds);
为啥一直报错。。。。。