[cfchenchen]

disp('请你确定t范围:');
t=input('t=');
if t>=0&t<=5
[y,z]=dsolve('Dy=2*y-2*y*z+t','Dz=-2*z+2*t','y(0)=10','z(0)=10');
y=simple(y) % 将y化简
z=simple(z) % 将y化简
end
if t>=5&t<=10
[y,z]=dsolve('Dy=y+y*z+t','Dz=z+2*t','y(0)=10','z(0)=10');
y=simple(y) % 将y化简
z=simple(z) % 将y化简
end