由a/（b-c）+b/（c-a）+c/（a-b）=0得[a/（b-c）+b/（c-a）+c/（a-b）][（1/(b-c)+1/(c-a)+1/(a-b)]=0拆开得[a/(b-c)2+b/(c-a)2+c/(a-b)2]+(a+b)/[(b-c)(c-a)]+(b+c)/[(c-a)(a-b)]+(c+a)/[(a-b)(b-c)]=0即[a/(b-c)2+...