>>461
dL/dt=2y1(dy1/dt)+2y2(dy2/dt)+2y3(dy3/dt)
=2y1(y2y3/I3-y2y3/I2)+2y2(-y3y1/I3+y3y1/I1)+2y3(y1y2/I2-y1y2/I1)
=2y1y2y3(1/I3-1/I2-1/I3+1/I1+1/I2-1/I1)
=0
dK/dt=(y1/I1)(dy1/dt)+(y2/I2)(dy2/dt)+(y3/I3)(dy3/dt)
=(y1/I1)(y2y3/I3-y2y3/I2)+(y2/I2)(-y3y1/I3+y3y1/I1)+(y3/I3)(y1y2/I2-y1y2/I1)
=y1y2y3{1/(I1I3)-1/(I1I2)-1/(I2I3)+1/(I2I1)+1/(I3I2)-1/(I3I1)}
=0