y/(y^2+1)dy=dx/(x^2-1)

dy/dx=x(1+y^2)/y通解 从(dx)/(dy)=1/y '导出：(d^2x)/(dy^2)=-y''/(y')^3 dy/dx,y=(1+x+x^2)e^x 试从dx/dy=1/y'导出：d^2x/dy^2=-y''/（y')^3 题目中关于d[1/y']/dx}*[dx/dy dy/dx-2y/(x+1)=(x+1)^2 dy/dx-2y/(1+x)=(x+1)^3 dy/dx=(e^x+x)(1+y^2)通解 (x^2)dy+（y^2)dx=dx-dy y=1(2x+1) 求dy/dx 求解微分方程dy/dx+x/2y=1/2 dy/dx=1+x+y^2+xy^2 x^2+xy+y^3=1,求dy/dx