matlab:dy/dx-x*sin(x+y)=0;y(1)=0

来源：学生作业帮编辑：搜搜做题作业网作业帮分类：综合作业时间：2024/05/09 15:34:26

因为当你输入
dsolve('Dy=x*sin(x+y)','y(1)=0')时,注意,没有指明自变量,matlab默认自变量是t,因此x被看作了常数,此时y(1)=0可能是个有问题的初值,所以不行.这也就是楼上的结果为什么会出现t的原因.
本题正
>> syms x y;
>> dsolve('Dy=x*sin(x+y)','x')
Warning: Explicit solution could not be found.
> In dsolve at 330

ans =

[ empty sym ]
说明matlab解不出来,变一下形.
令z=x+y,则dy/dx=dz/dx-1,原方程化为dz/dx-1-xsinz=0, z(1)=1
>> dsolve('Dz=x*sinz+1','z(1)=1','x')

ans =

1/2*x^2*sinz+x-1/2*sinz
然后将z换回x+y就行了.

matlab:能用matlab将 dy/dx=x*sin(x+y) 解, Dy/Dx + y = x , y(0) = 1 求解下列微分方程 ①dy/dx=(x+y)/(x-y)②（x-y)ydx-x^2dy=0③dy/dt+ytant=sin y=sin[sin(x^2)] 则dy/dx=? y=sin(x+y) 求dy/dx dy/dx=y/(sin(y)-x) 的积分求微分方程x*dy/dx+x+sin(x+y)=0的通解 d{cos(x-y)=sin(x-y)(dx-dy)这里dx-dy是什么意思呢? (x+y)dy+(x-y)dx=0求通解 x=sin(y/x)+e^2 求dy/dx 求方程[xcos(x+y)+sin(x+y)]dx+xcos(x+y)dy=0的通解, dx/dt=y dy/dy=x x(0)=-1 y(0)=0