数学问题,归一化: U1=1/(1+X); U2=1/(1+Y); U3=1/(1+X//Y); 设X>Y,则: U2-U1=U3-U2,即: 1/(1+Y)-1/(1+X)=1/(1+X//Y)-1/(1+Y);即: 2/(1+Y)-1/(1+X)=(X+Y)/(X+Y+X.Y); 左边通分得 (2X-Y+1)/(XY+X+Y+1)=(X+Y)/(XY+X+Y) 左右分母交换相乘得: 2(X^2)Y-X(Y^2)+2(X^2)-(Y^2)+2XY+X+Y=(X^2)Y+X(Y^2)+(X^2)+(Y^2)+2XY+X+Y 化简得: (X^2)(Y+1)=2(Y^2)(X+1) 如果X对Y存在极值,求导后结果为0,化简后得到极点X=2Y.
|