[-(-(cos(A)*Xv-sin(A)*Yv)*(-R*(Fx*Zv-Fz*Xv-Mgy)*cos(A)+((Flx+Fy)*Zv-Fz*Yv-Mgx)*R*sin(A)-Zv*Mgz-Mgx*Xv+Mgy*Yv)*cos(B)+((-Fx*Zv+Fz*Xv+Mgy)*cos(A)+((Flx+Fy)*Zv-Fz*Yv-Mgx)*sin(A))*Zv*sin(B)*R)*u/((-(cos(A)*Xv-sin(A)*Yv)*((-R*u-Xv*u+Zv)*cos(A)+u*Yv*(sin(A)-1))*cos(B)+Zv*sin(B)*((-R*u-Xv*u+Zv)*cos(A)+u*sin(A)*Yv))*R)]≤[u*(((cos(A)*Xv-sin(A)*Yv)*(-R*(Fx*Zv-Fz*Xv-Mgy)*cos(A)+((Flx+Fy)*Zv-Fz*Yv-Mgx)*R*sin(A)-Zv*Mgz-Mgx*Xv+Mgy*Yv)*cos(B)-((-Fx*Zv+Fz*Xv+Mgy)*cos(A)+((Flx+Fy)*Zv-Fz*Yv-Mgx)*sin(A))*Zv*sin(B)*R)/((-(cos(A)*Xv-sin(A)*Yv)*((-R*u-Xv*u+Zv)*cos(A)+u*Yv*(sin(A)-1))*cos(B)+Zv*sin(B)*((-R*u-Xv*u+Zv)*cos(A)+u*sin(A)*Yv))*R)
0＜A＜20，0＜B＜20
求 u
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