Question

用matlab怎么求解多元一次微分方程组

Answer 1

如果是常微分方程，可以用dsolve函数。该函数可以解单变量常微分方程或者多变量常微分方程组，所以5个变量也不在话下。调用格式如下：[y1,,yN]=dsolve(eqns)solvesthesystemofordinarydifferentialequationseqnsandassignsthesolutionstothevariablesy1,,yN.如果有初始条件，可以把条件一起传给函数来定解：[y1,,yN]=dsolve(eqns,conds)solvesthesystemofordinarydifferentialequationseqnswiththeinitialorboundaryconditionsconds.给出一个2个变量的微分方程组求解代码：symsx(t)y(t)z=dsolve(diff(x)==y,diff(y)==-x,x(0)==1,y(0)==1);x=z.x,y=z.y运行结果为：x=cos(t)+sin(t)y=cos(t)-sin(t)