由题意知：2a²/(1+a²)=b,2c²/(1+c²)=a则：a-b=a-2a²/(1+a²)=a(a-1)²/(1+a²)≧0所以：a≧b同理：c-a=c-2c²/(1+c²)=c(c-1)²/(1+c²)≧0即：c≧a综上所述...