因为a*(1/b+1/c)+b*(1/a+1/c)+c*(1/a+1/b)=0,所以a*(1/a+1/b+1/c)+b*(1/a+1/b+1/c)+c*(1/a+1/b+1/c)=3即(a+b+c)(1/a+1/b+1/c)=3由Cauchy不等式(a+b+c)(1/a+1/b+1/c)>=3,当且仅当a=b=c时等号成立又a^2+b^2+c^2=1,所以a^2=b^2=c^2=1/3因此a=b=c=√3/3或a=b=c=-√3/3