问题描述:
求积分,dy/dx=(x-y-1)/(x+y+1)
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方程变为dY/dX=(X-Y)/(X+Y),令u=(Y/X),代入,得(1+u)du/(1-2u-u^2)=-dX/X,积分得1-2u-u^2=Cx^2.
我不懂:u=(Y/X),代入,得(1+u)du/(1-2u-u^2)=-dX/dX,具体怎么代入得到?
.
.
方程变为dY/dX=(X-Y)/(X+Y),令u=(Y/X),代入,得(1+u)du/(1-2u-u^2)=-dX/X,积分得1-2u-u^2=Cx^2.
我不懂:u=(Y/X),代入,得(1+u)du/(1-2u-u^2)=-dX/dX,具体怎么代入得到?
问题解答:
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