你这个初始条件都没给,我假设y(0)=0,y'应该是对x求导吧。f=dsolve('(y+2)*Dy=x','y(0)=0','x');fh=str2func(['@(x)' vectorize(char(f))]);x=0:100;y=fh(x);plot(x,y)
[x,y,z]=solve('x^2-5*y^2+7*z^2+12=0 ','3*x*y+x*z-11*x=0','2*y*z+40*x=0')