f(x)满足(x-y)f(x+y)-(x+y)f(x-y)=4xy(x2-y2) 求f(x)朋友们迅速阿,我快挺不住了!

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f(x)满足(x-y)f(x+y)-(x+y)f(x-y)=4xy(x2-y2) 求f(x)朋友们迅速阿,我快挺不住了!
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f(x)满足(x-y)f(x+y)-(x+y)f(x-y)=4xy(x2-y2) 求f(x)朋友们迅速阿,我快挺不住了!
f(x)满足(x-y)f(x+y)-(x+y)f(x-y)=4xy(x2-y2) 求f(x)
朋友们迅速阿,我快挺不住了!

f(x)满足(x-y)f(x+y)-(x+y)f(x-y)=4xy(x2-y2) 求f(x)朋友们迅速阿,我快挺不住了!
f(x)=x三次方
(x-y)f(x+y)-(x+y)f(x-y)=4xy(x2-y2)
两边同除以(x2-y2)
则可知f(x+y)/(x+y)-f(x-y)/(x-y)=4xy
所以f(x+y)/(x+y)=(x+y)^2
所以f(x+y)=(x+y)^3
所以f(x)=x^3

快挺不住 ????

设x+y=m x-y=n
x2+2xy+y2=m2
x2-2xy+y2=n2
4xy=m2-n2
nf(m)-mf(n)=4mn(m2-n2)
f(m)/m-f(n)/n=4(m2-n2)
设f(x)/x=g(x)
g(m)-g(n)=4m2-4n2
g(x)=4x2
f(x)=4x3