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y dy = - x dx y2/2 = - x2/2 + C y2 = - x2 + C x2 + y2 = C 所以通解为x2 + y2 = 0 或 x2 + y2 = C 合并就是x2 + y2 = C
(x^2 3xy^2)dx (3x^2y 2y^2)dy=0求该全微分方程通解φ(y) = ∫ 2y² dy = 2y³/3 + C1 于是u(x,y) = x³/3 + 3x²y²/2 + 2y³/3 + C1 方程通解为u(x,y) = C 即x³/3 + 3x²y²/2 + 2y³/3 = C
求齐次方程的通解:1.(x^2+y^2)dx-xydy=0 2.(x^3+y^3)dx-3xy^2dy=01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/...
(x^3+y^3)dx-3xy^2dy=0求齐次方程的通解解:dy/dx=(x³+y³)/3xy²=(1/3)[(x/y)²+(y/x)]=(1/3)[1/(y/x)²+(y/x)]令y/x=u,则y=ux,dy/dx=u+x(du/dx),代入上式得:u+x(du/dx)=(1/3)[(1/u²)+u]故有x(du/dx)=1/(3u²)-(2/3)u=(1-2u³)/...
求微分方程x^2ydx-(x^3+y^3)dy=0的通解x^2ydx-(x^3+y^3)dy=0 变形:dx/dy=x/y+(y/x)^2 设x/y=u,x=yu dx/dy=u+ydu/dy u+ydu/dy=u+(1/u)^2 ydu/dy=(1/u)^2 u^2du=dy/y 通解u^3=3lny+lnC (x/y)^3=e^(Cy^3)
求方程(y^2+xy^2)dx+(x^2-yx^2)dy=0的通解?∵(y^2+xy^2)dx+(x^2-yx^2)dy=0 ==>y²(1+x)dx+x²(1-y)dy=0 ==>[(y-1)/y²]dy=[(1+x)/x²]dx ==>(1/y-1/y²)dy=(1/x+1/x²)dx ==>ln|y|+i/y=ln|x|-1/x+C1 (C1是积分常数)==>ln|y|-ln|x|=-1/x-1/y+C...
求解(x^3+y^3)dx-3xy^2dy=0的通解 要详细过程 谢谢了……x^3dx=3xy^2dy-y^3dx x^3dx=xdy^3-y^3dx xdx=dy^3/x+y^3d(1/x)通解x^2/2=y^3/x+C
微分方程y^3dx+2(x^3-xy^2)dy=0的通解为多少解:∵(3xy+x^2)dy+(y^2+xy)dx=0==>2y(3xy+x^2)dy+2y(y^2+xy)dx=0(等式两端同乘2y)==>2(3xy^2dy+y^3dx)+2(x^2ydy+xy^2dx)=0==>2d(xy^3)+d(x^2y^2)=0==>2∫d(xy^3)+∫d(x^2y^2)=0==>2xy^3+x^2y^2=C(C是常数)∴此方程的通解是2xy^3+x^2y^...
(x³+y³)dx-3xy²dy=0此微分方程的通解为x^3-2y^2=C。 ∵(x^3+y^3)dx-3xy^2dy=0, ∴x^3dx=3xy^2dx-y^3dx, ∴xdx=[xd(y^3)-y^3dx]/x^2, ∴(1/2)d(x^2)=d(y^3/x), ∴(1/2)x^2=C+y^3/x, ∴x^3-2y^2=C。 ∴原微分方程的通解是:x^3-2y^2=C。 扩展资料: 微分方程指含有未知函数及其导...
方程(X^3- 3xy^2 )dx + ( y ^3-3x^2 y)dy = 0的通解 微分方程,求详细解 ...凑微分法 (x³-3xy²)dx+(y³-3x²y)dy=0 d[(x^4)/4-1.5x²y²+(y^4)/4]=0 (x^4)/4-1.5x²y²+(y^4)/4=C 选 B