1.求下列方程的解:-|||-(1) dfrac (dy)(dx)=2xy ,并求满足初值条件 x=0 ,y=1 的特解;-|||-(2) ^2dx+(x+1)dy=0 ,并求满足初值条件 x=0 ,y=1 的特解;-|||-(3) dfrac (dy)(dx)=dfrac (1+{y)^2}(xy+{x)^3y}-|||-(4) (1+x)ydx+(1-y)xdy=0 ;-|||-(5) (y+x)dy+(x-y)dx=0 ;-|||-(6) dfrac (dy)(dx)-y+sqrt ({x)^2-(y)^2}=0 ;-|||-(7) tan ydx-cot xdy=0 ;1.求下列方程的解:-|||-(1) dfrac (dy)(dx)=2xy ,并求满足初值条件 x=0 ,y=1 的特解;-|||-(2) ^2dx+(x+1)dy=0 ,并求满足初值条件 x=0 ,y=1 的特解;-|||-(3) dfrac (dy)(dx)=dfrac (1+{y)^2}(xy+{x)^3y}-|||-(4) (1+x)ydx+(1-y)xdy=0 ;-|||-(5) (y+x)dy+(x-y)dx=0 ;-|||-(6) dfrac (dy)(dx)-y+sqrt ({x)^2-(y)^2}=0 ;-|||-(7) tan ydx-cot xdy=0 ;