(x2+y2)dx-xydy=0dy/dx=(x²+y²)/(xy)dy/dx=((x/y)²+1)/(x/y)令u=y/x则dy=du×x+dx×udy/dx=(du/dx)×x+u代入得(du/dx)×x+u=(u²+1)/u=u+1/udu/dx=1/(xu)u×du=dx/x两边积分得(1/2)u²=lnx+C将u=y/x回代(1/2)(y/x)²=(lnx)+Cy²=...
2. (y^2+x^2)dx-xydy=0解:移项,同除以dx,同除以Xy,方程化为(dy)/(dx)=(齐次方程标准形u=y/x (dy)/(dx)=。令× ,求
(x^2+y^2-xy)dx-xydy=0 即 dy/dx=(x^2+y^2-xy)/(xy)=x/y+y/x-1 是齐次方程 令 y=px, 则 微分方程化为 p+xdp/dx=1/p+p-1 xdp/dx=1/p-1=(1-p)/p pdp/(p-1)=-dx/x p+ln(p-1)=-lnx+lnC x(p-1)e^p=C 通解是 (y-x)e^(y/x)=C ...
1解: (x^2+y^2)dx-xydy=0;dy/dx=(x+y)/(xy);dy/dx=((x/y)+1)/(x/y); 令u=y/x,则dy=du*x+dx*u,dy/dx=(du/dx)*x+u, 代入得(du/dx)*x+u=(u+1)/u=u+1/u,du/dx=1/(xu),*du=dx/x, 两边积分得 (1/2)u=lnx+C 将u=y/x回代,(1/2)(y/...
所以微分方程的通解为:y2=x(ln|x|+c). 29293 (x^2+y^2)dx+2xydy=0怎么求通解! 你未学过导数?d(x^3/3)/dx = 1/3*3x^2 = x^2相反就是积分过程d(xy^2)/dx = y^2*dx/dx + x*d(y^2)/dx = y^2 + 2xy*dy/dx = y^2dx + 2xydy 35256 求(x^2+y^2)dx-xydy=0微分方程...
【题目】求下列齐次方程的通解:(1) xy'-y-√(y^2-x^2)=0 :(2) x(dy)/(dx)=ylny/x ;(3) (x^2+y^2)dx-xydy=0 ;(4) (x^3+y^3)dx-3xy^2dy=0 ; 相关知识点: 试题来源: 解析 【解析】 解(1》当x0时可将原方程写成 y'=y/x+√((y/x)^2-1) -1,令 =...
3.求下列微分方程的通解或在给定初始条件下的特解:(1) (x^2+y^2)dx-2xydy=0 (2) (xy-x^2)dy=y^2dx(3) 3xy^2dy=(2y^
这是齐次方程,因为它可化成dy/dy=((y^2-x^2)/(xy)=y/x一x/y,令u=y/x,则y=ux,dy/dx=d(ux)/dx=xdu/dx+u,即xdu/dx+u=u-1/u,xdu/dx=-1/u,udu=-dx/x,两端积分,得u^2=-2lnx+lnC,即(y/x)^2=ln(C/x^2),当x=1,y=1,代入上式...
一阶齐次微分方程 (x^2+y^2)dx-xydy=0 dy/dx=(x²+y²)/(xy)dy/dx=((x/y)²+1)/(x/y)令u=y/x 则dy=du*x+dx*u dy/dx=(du/dx)*x+u 代入得 (du/dx)*x+u=(u²+1)/u=u+1/u du/dx=1/(xu)u*du=dx/x 两边积分得 (1/2)u²=...
∵(3x²+2xy-y²)dx+(x²-xy)dy=90同除以x^2(3+2y/x-(y/x)^2)dx+(1-y/x)dy=0y/x=uy=ux y'=u'x+u(3+2u-u^2)+(1-u)(u'x+u)=0(3+2u-u^2)/(u-1)-u=u'x(3+2u-u^2-u^2+u)/(u-1)=u'x(-2u^2+3u+3)/(u-1)=u'x(u^2-1.5u-1.5)/(u-1)=-1/...