设f(x-y,y/x)=xy,则f(xy,x+y)等于什么

问题描述:

设f(x-y,y/x)=xy,则f(xy,x+y)等于什么

设a-b=xy(1),b/a=x+y(2)联合等式(1)、(2)可得:a=xy/(1-x-y),b=(x²y+xy²)/(1-x-y)由题意可知f(x-y,y/x)=xy,则有f(a-b,b/a)=ab={xy/(1-x-y)}*{(x²y+xy²)/(1-x-y...