本文给出Cauchy-三次函数方程f(x1+x2,2y1+y2)+f(x1+x2,2y1-y2)=2 f(x1,y1+y2)+2f(x1，y1-y2)+12 f(x1,y1)+2 f(x2,y1+y2)+2 f(x2,y1......