设：p点坐标为(x,y)m(-1,0),n(1,0)mp=(x+1,y)mn=(2,0)pm=(-1-x,-y)pn=(1-x,-y)nm=(-2,0)np=(x-1,y)mp*mn=2x+2pm*pn=x²+y²-1nm*np=2-2x公差小于零,那么后数比前数小,且有关系：(mp*mn)+(nm*np)=2(pm*pn)即2...