求K的值,已知abc的积不等于零,a/(b+c)=b/(c+a)=c/(a+b)=K.解题过程.
问题描述:
求K的值,已知abc的积不等于零,a/(b+c)=b/(c+a)=c/(a+b)=K.解题过程.
我想的也是1/2和-1啊,但是要的是解题过程,老师谢谢指教!!!
答
k=a/(b+c)=b/(c+a)=c/(a+b) (1)当a+b+c不=0 时. k=a/(b+c)=b/(a+c)=c/(a+b) =(a+b+c)/[(b+c)+(a+c)+(a+b)] =(a+b+c)/(2a+2b+2c) =1/2 (2)当a+b+c=0 时. a=-(b+c), b=-(a+c), c=-(a+b), k=a/(b+c)=b/(a+c)=c/(a+b) =-...