设f(x+y，y/x)=x2-y2(y≠一1)，则f(x，y)等于()
A.y2[(1-x2)/(1+y)2 B.x[(1-y2)/(1+y)2] C.x2[(1-y)2/(1+y)2] D.y[(1-x2)/(1+y)2]正确答案C
设f(x+y，y/x)=x2-y2(y≠一1)，则f(x，y)等于()
A.y2[(1-x2)/(1+y)2 B.x[(1-y2)/(1+y)2] C.x2[(1-y)2/(1+y)2] D.y[(1-x2)/(1+y)2]正确答案C
